5th Workshop on the Scientific Cooperation between German Research Centres and JINR

The PAX ProjectThe PAX ProjectSpin Physics at GSISpin Physics at GSI

Spokespersons

Paolo Lenisa Ferrara University lenisamaildesyde

Frank Rathmann FZ-Juumllich frathmannfz-juelichde

Polarized Antiproton Experimentswwwfz-juelichdeikppax

Central Physics IssueCentral Physics Issue

Transversity distribution of the nucleon

ndash last leading-twist missing piece of the QCD description of the partonic structure of the nucleon

ndash directly accessible uniquely via the double transverse spin asymmetry ATT in the Drell-Yan production of lepton pairs

ndash theoretical expectations for ATT in DY 30-40 bull transversely polarized antiprotons bull transversely polarized proton target

ndash definitive observation of h1q

(xQ2) of the proton for the valence quarks

Leading Twist Distribution Functions Leading Twist Distribution Functions

12 12

L L

+f1(x)

h1(x)

proton

protonrsquo

quark

quarkrsquo

u = 12(uR + uL)u = 12(uR - uL)

No probabilistic interpretation in the helicity base (off diagonal)

Probabilistic interpretation in helicity base

q(x) spin averaged

(well known)

q(x) helicity diff(known)

q(x) helicity flip(unknown)

12 12

R R

12 12

L L

-12 12

R R

g1(x)

Transversitybase

12 -12

R L

-

Evaluation by Evaluation by QCD Program Advisory Committee (July QCD Program Advisory Committee (July

2004)2004)STI ReportYour LoI has convinced the QCD-PAC

a)that Polarization must be included into the design of FAIR from the beginning and

b)that the presently proposed scheme is not optimized as to the physics You [hellip] are invited and encouraged to design a world-class facility with unequalled degree of polarization of antiprotons

Common Report

[hellip] The PAC considers the spin physics of extreme interest and the building of an antiproton polarized beam as a unique possibility for the FAIR Project

[hellip] The unique physics opportunities made possible with polarized antiproton beams andor polarized target are extremely exciting especially in double spin measurements

[hellip] It would be very unfortunate if decisions about the facility made now later preclude the science

1 10 100 T (MeV)

σEM

|| (

mb

)

100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Exploitation of Spin TransferExploitation of Spin Transfer

epep PAX will employ spin-

transfer from polarized electrons of the target to

antiprotonsHydrogen gas target ①+② in strong field (300 mT)

Pe=0993Pz=0007

(QED Process calculable)

01

02

03

04B

eam

Pola

riza

tion

P(2

middotτbeam)

10 T (MeV)100

EM only

5

10

30

20

40

Ψacc=50 mrad

0

1

Filter Test T = 23 MeV Ψacc= 44 mrad

Buildup in HESR (800 MeV)

F Rathmann et al PRL 94 014801 (2005)

Antiproton Beam PolarizationAntiproton Beam Polarization

Transversity in Drell-Yan processesTransversity in Drell-Yan processes

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

AATTTT for PAX kinematic conditions for PAX kinematic conditions

RHIC τ=x1x2=M2s~10-3 rarr Exploration of the sea quark content (polarizations small) ATT very small (~ 1 )

TT

TT

a

A

T=22 GeV (s=67 GeV)

T=15 GeV(s=57 GeV)

Anselmino et al PLB 59497

(2004)

010

015

025

03

xF=x1-x2

02 04 060

ATTaTT gt 03Models predict |h1

u|gtgt|h1d|

)Mx(u)Mx(u

)Mx(h)Mx(haA

21

21

21

u1

21

u1

TTTT

)qqqwhere( pp

Main contribution to Drell-Yan events at PAX from x1~x2~τdeduction of x-dependence of h1

u(xM2)

PAX M2~10 GeV2 s~30-50 GeV2 τ=x1x2=M2s~02-03

rarr Exploration of valence quarks (h1q(xQ2) large)

Similar predictions by Efremov et al

Eur Phys J C35 207 (2004)

xF=x1-x2

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR (COSY-like) at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons(also fixed target experiments possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

AATTTT for PAX kinematic conditions for PAX kinematic conditionsFixed TargetFixed Target vsvs Collider Collider

Anselmino et al PLB 59497 (2004)

22 GeVc

15+35

22 GeVc fixed target

15+35 collider

15 + 15 collider

Collider Options for Transversity measurementbull 15 GeVc + 15 GeVc s=1000 GeV2 too highbull 15 GeVc + 35 GeVc s=220 GeV2 idealideal

Similar predictions by Efremov et al Eur Phys J C35 207

(2004)

Conceptual Detector DesignConceptual Detector Design

~3 m

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Central Physics IssueCentral Physics Issue

Transversity distribution of the nucleon

ndash last leading-twist missing piece of the QCD description of the partonic structure of the nucleon

ndash directly accessible uniquely via the double transverse spin asymmetry ATT in the Drell-Yan production of lepton pairs

ndash theoretical expectations for ATT in DY 30-40 bull transversely polarized antiprotons bull transversely polarized proton target

ndash definitive observation of h1q

(xQ2) of the proton for the valence quarks

Leading Twist Distribution Functions Leading Twist Distribution Functions

12 12

L L

+f1(x)

h1(x)

proton

protonrsquo

quark

quarkrsquo

u = 12(uR + uL)u = 12(uR - uL)

No probabilistic interpretation in the helicity base (off diagonal)

Probabilistic interpretation in helicity base

q(x) spin averaged

(well known)

q(x) helicity diff(known)

q(x) helicity flip(unknown)

12 12

R R

12 12

L L

-12 12

R R

g1(x)

Transversitybase

12 -12

R L

-

Evaluation by Evaluation by QCD Program Advisory Committee (July QCD Program Advisory Committee (July

2004)2004)STI ReportYour LoI has convinced the QCD-PAC

a)that Polarization must be included into the design of FAIR from the beginning and

b)that the presently proposed scheme is not optimized as to the physics You [hellip] are invited and encouraged to design a world-class facility with unequalled degree of polarization of antiprotons

Common Report

[hellip] The PAC considers the spin physics of extreme interest and the building of an antiproton polarized beam as a unique possibility for the FAIR Project

[hellip] The unique physics opportunities made possible with polarized antiproton beams andor polarized target are extremely exciting especially in double spin measurements

[hellip] It would be very unfortunate if decisions about the facility made now later preclude the science

1 10 100 T (MeV)

σEM

|| (

mb

)

100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Exploitation of Spin TransferExploitation of Spin Transfer

epep PAX will employ spin-

transfer from polarized electrons of the target to

antiprotonsHydrogen gas target ①+② in strong field (300 mT)

Pe=0993Pz=0007

(QED Process calculable)

01

02

03

04B

eam

Pola

riza

tion

P(2

middotτbeam)

10 T (MeV)100

EM only

5

10

30

20

40

Ψacc=50 mrad

0

1

Filter Test T = 23 MeV Ψacc= 44 mrad

Buildup in HESR (800 MeV)

F Rathmann et al PRL 94 014801 (2005)

Antiproton Beam PolarizationAntiproton Beam Polarization

Transversity in Drell-Yan processesTransversity in Drell-Yan processes

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

AATTTT for PAX kinematic conditions for PAX kinematic conditions

RHIC τ=x1x2=M2s~10-3 rarr Exploration of the sea quark content (polarizations small) ATT very small (~ 1 )

TT

TT

a

A

T=22 GeV (s=67 GeV)

T=15 GeV(s=57 GeV)

Anselmino et al PLB 59497

(2004)

010

015

025

03

xF=x1-x2

02 04 060

ATTaTT gt 03Models predict |h1

u|gtgt|h1d|

)Mx(u)Mx(u

)Mx(h)Mx(haA

21

21

21

u1

21

u1

TTTT

)qqqwhere( pp

Main contribution to Drell-Yan events at PAX from x1~x2~τdeduction of x-dependence of h1

u(xM2)

PAX M2~10 GeV2 s~30-50 GeV2 τ=x1x2=M2s~02-03

rarr Exploration of valence quarks (h1q(xQ2) large)

Similar predictions by Efremov et al

Eur Phys J C35 207 (2004)

xF=x1-x2

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR (COSY-like) at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons(also fixed target experiments possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

AATTTT for PAX kinematic conditions for PAX kinematic conditionsFixed TargetFixed Target vsvs Collider Collider

Anselmino et al PLB 59497 (2004)

22 GeVc

15+35

22 GeVc fixed target

15+35 collider

15 + 15 collider

Collider Options for Transversity measurementbull 15 GeVc + 15 GeVc s=1000 GeV2 too highbull 15 GeVc + 35 GeVc s=220 GeV2 idealideal

Similar predictions by Efremov et al Eur Phys J C35 207

(2004)

Conceptual Detector DesignConceptual Detector Design

~3 m

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Leading Twist Distribution Functions Leading Twist Distribution Functions

12 12

L L

+f1(x)

h1(x)

proton

protonrsquo

quark

quarkrsquo

u = 12(uR + uL)u = 12(uR - uL)

No probabilistic interpretation in the helicity base (off diagonal)

Probabilistic interpretation in helicity base

q(x) spin averaged

(well known)

q(x) helicity diff(known)

q(x) helicity flip(unknown)

12 12

R R

12 12

L L

-12 12

R R

g1(x)

Transversitybase

12 -12

R L

-

Evaluation by Evaluation by QCD Program Advisory Committee (July QCD Program Advisory Committee (July

2004)2004)STI ReportYour LoI has convinced the QCD-PAC

a)that Polarization must be included into the design of FAIR from the beginning and

b)that the presently proposed scheme is not optimized as to the physics You [hellip] are invited and encouraged to design a world-class facility with unequalled degree of polarization of antiprotons

Common Report

[hellip] The PAC considers the spin physics of extreme interest and the building of an antiproton polarized beam as a unique possibility for the FAIR Project

[hellip] The unique physics opportunities made possible with polarized antiproton beams andor polarized target are extremely exciting especially in double spin measurements

[hellip] It would be very unfortunate if decisions about the facility made now later preclude the science

1 10 100 T (MeV)

σEM

|| (

mb

)

100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Exploitation of Spin TransferExploitation of Spin Transfer

epep PAX will employ spin-

transfer from polarized electrons of the target to

antiprotonsHydrogen gas target ①+② in strong field (300 mT)

Pe=0993Pz=0007

(QED Process calculable)

01

02

03

04B

eam

Pola

riza

tion

P(2

middotτbeam)

10 T (MeV)100

EM only

5

10

30

20

40

Ψacc=50 mrad

0

1

Filter Test T = 23 MeV Ψacc= 44 mrad

Buildup in HESR (800 MeV)

F Rathmann et al PRL 94 014801 (2005)

Antiproton Beam PolarizationAntiproton Beam Polarization

Transversity in Drell-Yan processesTransversity in Drell-Yan processes

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

AATTTT for PAX kinematic conditions for PAX kinematic conditions

RHIC τ=x1x2=M2s~10-3 rarr Exploration of the sea quark content (polarizations small) ATT very small (~ 1 )

TT

TT

a

A

T=22 GeV (s=67 GeV)

T=15 GeV(s=57 GeV)

Anselmino et al PLB 59497

(2004)

010

015

025

03

xF=x1-x2

02 04 060

ATTaTT gt 03Models predict |h1

u|gtgt|h1d|

)Mx(u)Mx(u

)Mx(h)Mx(haA

21

21

21

u1

21

u1

TTTT

)qqqwhere( pp

Main contribution to Drell-Yan events at PAX from x1~x2~τdeduction of x-dependence of h1

u(xM2)

PAX M2~10 GeV2 s~30-50 GeV2 τ=x1x2=M2s~02-03

rarr Exploration of valence quarks (h1q(xQ2) large)

Similar predictions by Efremov et al

Eur Phys J C35 207 (2004)

xF=x1-x2

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR (COSY-like) at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons(also fixed target experiments possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

AATTTT for PAX kinematic conditions for PAX kinematic conditionsFixed TargetFixed Target vsvs Collider Collider

Anselmino et al PLB 59497 (2004)

22 GeVc

15+35

22 GeVc fixed target

15+35 collider

15 + 15 collider

Collider Options for Transversity measurementbull 15 GeVc + 15 GeVc s=1000 GeV2 too highbull 15 GeVc + 35 GeVc s=220 GeV2 idealideal

Similar predictions by Efremov et al Eur Phys J C35 207

(2004)

Conceptual Detector DesignConceptual Detector Design

~3 m

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Evaluation by Evaluation by QCD Program Advisory Committee (July QCD Program Advisory Committee (July

2004)2004)STI ReportYour LoI has convinced the QCD-PAC

a)that Polarization must be included into the design of FAIR from the beginning and

b)that the presently proposed scheme is not optimized as to the physics You [hellip] are invited and encouraged to design a world-class facility with unequalled degree of polarization of antiprotons

Common Report

[hellip] The PAC considers the spin physics of extreme interest and the building of an antiproton polarized beam as a unique possibility for the FAIR Project

[hellip] The unique physics opportunities made possible with polarized antiproton beams andor polarized target are extremely exciting especially in double spin measurements

[hellip] It would be very unfortunate if decisions about the facility made now later preclude the science

1 10 100 T (MeV)

σEM

|| (

mb

)

100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Exploitation of Spin TransferExploitation of Spin Transfer

epep PAX will employ spin-

transfer from polarized electrons of the target to

antiprotonsHydrogen gas target ①+② in strong field (300 mT)

Pe=0993Pz=0007

(QED Process calculable)

01

02

03

04B

eam

Pola

riza

tion

P(2

middotτbeam)

10 T (MeV)100

EM only

5

10

30

20

40

Ψacc=50 mrad

0

1

Filter Test T = 23 MeV Ψacc= 44 mrad

Buildup in HESR (800 MeV)

F Rathmann et al PRL 94 014801 (2005)

Antiproton Beam PolarizationAntiproton Beam Polarization

Transversity in Drell-Yan processesTransversity in Drell-Yan processes

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

AATTTT for PAX kinematic conditions for PAX kinematic conditions

RHIC τ=x1x2=M2s~10-3 rarr Exploration of the sea quark content (polarizations small) ATT very small (~ 1 )

TT

TT

a

A

T=22 GeV (s=67 GeV)

T=15 GeV(s=57 GeV)

Anselmino et al PLB 59497

(2004)

010

015

025

03

xF=x1-x2

02 04 060

ATTaTT gt 03Models predict |h1

u|gtgt|h1d|

)Mx(u)Mx(u

)Mx(h)Mx(haA

21

21

21

u1

21

u1

TTTT

)qqqwhere( pp

Main contribution to Drell-Yan events at PAX from x1~x2~τdeduction of x-dependence of h1

u(xM2)

PAX M2~10 GeV2 s~30-50 GeV2 τ=x1x2=M2s~02-03

rarr Exploration of valence quarks (h1q(xQ2) large)

Similar predictions by Efremov et al

Eur Phys J C35 207 (2004)

xF=x1-x2

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR (COSY-like) at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons(also fixed target experiments possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

AATTTT for PAX kinematic conditions for PAX kinematic conditionsFixed TargetFixed Target vsvs Collider Collider

Anselmino et al PLB 59497 (2004)

22 GeVc

15+35

22 GeVc fixed target

15+35 collider

15 + 15 collider

Collider Options for Transversity measurementbull 15 GeVc + 15 GeVc s=1000 GeV2 too highbull 15 GeVc + 35 GeVc s=220 GeV2 idealideal

Similar predictions by Efremov et al Eur Phys J C35 207

(2004)

Conceptual Detector DesignConceptual Detector Design

~3 m

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

1 10 100 T (MeV)

σEM

|| (

mb

)

100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Exploitation of Spin TransferExploitation of Spin Transfer

epep PAX will employ spin-

transfer from polarized electrons of the target to

antiprotonsHydrogen gas target ①+② in strong field (300 mT)

Pe=0993Pz=0007

(QED Process calculable)

01

02

03

04B

eam

Pola

riza

tion

P(2

middotτbeam)

10 T (MeV)100

EM only

5

10

30

20

40

Ψacc=50 mrad

0

1

Filter Test T = 23 MeV Ψacc= 44 mrad

Buildup in HESR (800 MeV)

F Rathmann et al PRL 94 014801 (2005)

Antiproton Beam PolarizationAntiproton Beam Polarization

Transversity in Drell-Yan processesTransversity in Drell-Yan processes

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

AATTTT for PAX kinematic conditions for PAX kinematic conditions

RHIC τ=x1x2=M2s~10-3 rarr Exploration of the sea quark content (polarizations small) ATT very small (~ 1 )

TT

TT

a

A

T=22 GeV (s=67 GeV)

T=15 GeV(s=57 GeV)

Anselmino et al PLB 59497

(2004)

010

015

025

03

xF=x1-x2

02 04 060

ATTaTT gt 03Models predict |h1

u|gtgt|h1d|

)Mx(u)Mx(u

)Mx(h)Mx(haA

21

21

21

u1

21

u1

TTTT

)qqqwhere( pp

Main contribution to Drell-Yan events at PAX from x1~x2~τdeduction of x-dependence of h1

u(xM2)

PAX M2~10 GeV2 s~30-50 GeV2 τ=x1x2=M2s~02-03

rarr Exploration of valence quarks (h1q(xQ2) large)

Similar predictions by Efremov et al

Eur Phys J C35 207 (2004)

xF=x1-x2

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR (COSY-like) at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons(also fixed target experiments possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

AATTTT for PAX kinematic conditions for PAX kinematic conditionsFixed TargetFixed Target vsvs Collider Collider

Anselmino et al PLB 59497 (2004)

22 GeVc

15+35

22 GeVc fixed target

15+35 collider

15 + 15 collider

Collider Options for Transversity measurementbull 15 GeVc + 15 GeVc s=1000 GeV2 too highbull 15 GeVc + 35 GeVc s=220 GeV2 idealideal

Similar predictions by Efremov et al Eur Phys J C35 207

(2004)

Conceptual Detector DesignConceptual Detector Design

~3 m

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

01

02

03

04B

eam

Pola

riza

tion

P(2

middotτbeam)

10 T (MeV)100

EM only

5

10

30

20

40

Ψacc=50 mrad

0

1

Filter Test T = 23 MeV Ψacc= 44 mrad

Buildup in HESR (800 MeV)

F Rathmann et al PRL 94 014801 (2005)

Antiproton Beam PolarizationAntiproton Beam Polarization

Transversity in Drell-Yan processesTransversity in Drell-Yan processes

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

AATTTT for PAX kinematic conditions for PAX kinematic conditions

RHIC τ=x1x2=M2s~10-3 rarr Exploration of the sea quark content (polarizations small) ATT very small (~ 1 )

TT

TT

a

A

T=22 GeV (s=67 GeV)

T=15 GeV(s=57 GeV)

Anselmino et al PLB 59497

(2004)

010

015

025

03

xF=x1-x2

02 04 060

ATTaTT gt 03Models predict |h1

u|gtgt|h1d|

)Mx(u)Mx(u

)Mx(h)Mx(haA

21

21

21

u1

21

u1

TTTT

)qqqwhere( pp

Main contribution to Drell-Yan events at PAX from x1~x2~τdeduction of x-dependence of h1

u(xM2)

PAX M2~10 GeV2 s~30-50 GeV2 τ=x1x2=M2s~02-03

rarr Exploration of valence quarks (h1q(xQ2) large)

Similar predictions by Efremov et al

Eur Phys J C35 207 (2004)

xF=x1-x2

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR (COSY-like) at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons(also fixed target experiments possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

AATTTT for PAX kinematic conditions for PAX kinematic conditionsFixed TargetFixed Target vsvs Collider Collider

Anselmino et al PLB 59497 (2004)

22 GeVc

15+35

22 GeVc fixed target

15+35 collider

15 + 15 collider

Collider Options for Transversity measurementbull 15 GeVc + 15 GeVc s=1000 GeV2 too highbull 15 GeVc + 35 GeVc s=220 GeV2 idealideal

Similar predictions by Efremov et al Eur Phys J C35 207

(2004)

Conceptual Detector DesignConceptual Detector Design

~3 m

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Transversity in Drell-Yan processesTransversity in Drell-Yan processes

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

AATTTT for PAX kinematic conditions for PAX kinematic conditions

RHIC τ=x1x2=M2s~10-3 rarr Exploration of the sea quark content (polarizations small) ATT very small (~ 1 )

TT

TT

a

A

T=22 GeV (s=67 GeV)

T=15 GeV(s=57 GeV)

Anselmino et al PLB 59497

(2004)

010

015

025

03

xF=x1-x2

02 04 060

ATTaTT gt 03Models predict |h1

u|gtgt|h1d|

)Mx(u)Mx(u

)Mx(h)Mx(haA

21

21

21

u1

21

u1

TTTT

)qqqwhere( pp

Main contribution to Drell-Yan events at PAX from x1~x2~τdeduction of x-dependence of h1

u(xM2)

PAX M2~10 GeV2 s~30-50 GeV2 τ=x1x2=M2s~02-03

rarr Exploration of valence quarks (h1q(xQ2) large)

Similar predictions by Efremov et al

Eur Phys J C35 207 (2004)

xF=x1-x2

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR (COSY-like) at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons(also fixed target experiments possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

AATTTT for PAX kinematic conditions for PAX kinematic conditionsFixed TargetFixed Target vsvs Collider Collider

Anselmino et al PLB 59497 (2004)

22 GeVc

15+35

22 GeVc fixed target

15+35 collider

15 + 15 collider

Collider Options for Transversity measurementbull 15 GeVc + 15 GeVc s=1000 GeV2 too highbull 15 GeVc + 35 GeVc s=220 GeV2 idealideal

Similar predictions by Efremov et al Eur Phys J C35 207

(2004)

Conceptual Detector DesignConceptual Detector Design

~3 m

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

AATTTT for PAX kinematic conditions for PAX kinematic conditions

RHIC τ=x1x2=M2s~10-3 rarr Exploration of the sea quark content (polarizations small) ATT very small (~ 1 )

TT

TT

a

A

T=22 GeV (s=67 GeV)

T=15 GeV(s=57 GeV)

Anselmino et al PLB 59497

(2004)

010

015

025

03

xF=x1-x2

02 04 060

ATTaTT gt 03Models predict |h1

u|gtgt|h1d|

)Mx(u)Mx(u

)Mx(h)Mx(haA

21

21

21

u1

21

u1

TTTT

)qqqwhere( pp

Main contribution to Drell-Yan events at PAX from x1~x2~τdeduction of x-dependence of h1

u(xM2)

PAX M2~10 GeV2 s~30-50 GeV2 τ=x1x2=M2s~02-03

rarr Exploration of valence quarks (h1q(xQ2) large)

Similar predictions by Efremov et al

Eur Phys J C35 207 (2004)

xF=x1-x2

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR (COSY-like) at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons(also fixed target experiments possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

AATTTT for PAX kinematic conditions for PAX kinematic conditionsFixed TargetFixed Target vsvs Collider Collider

Anselmino et al PLB 59497 (2004)

22 GeVc

15+35

22 GeVc fixed target

15+35 collider

15 + 15 collider

Collider Options for Transversity measurementbull 15 GeVc + 15 GeVc s=1000 GeV2 too highbull 15 GeVc + 35 GeVc s=220 GeV2 idealideal

Similar predictions by Efremov et al Eur Phys J C35 207

(2004)

Conceptual Detector DesignConceptual Detector Design

~3 m

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR (COSY-like) at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons(also fixed target experiments possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

AATTTT for PAX kinematic conditions for PAX kinematic conditionsFixed TargetFixed Target vsvs Collider Collider

Anselmino et al PLB 59497 (2004)

22 GeVc

15+35

22 GeVc fixed target

15+35 collider

15 + 15 collider

Collider Options for Transversity measurementbull 15 GeVc + 15 GeVc s=1000 GeV2 too highbull 15 GeVc + 35 GeVc s=220 GeV2 idealideal

Similar predictions by Efremov et al Eur Phys J C35 207

(2004)

Conceptual Detector DesignConceptual Detector Design

~3 m

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons (also fixed target experiment possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons(also fixed target experiments possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

AATTTT for PAX kinematic conditions for PAX kinematic conditionsFixed TargetFixed Target vsvs Collider Collider

Anselmino et al PLB 59497 (2004)

22 GeVc

15+35

22 GeVc fixed target

15+35 collider

15 + 15 collider

Collider Options for Transversity measurementbull 15 GeVc + 15 GeVc s=1000 GeV2 too highbull 15 GeVc + 35 GeVc s=220 GeV2 idealideal

Similar predictions by Efremov et al Eur Phys J C35 207

(2004)

Conceptual Detector DesignConceptual Detector Design

~3 m

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

I CSR at FAIR (35 GeVc)a Formfactor measurement pp rarr e+e-

- unpolarized antiproton beam on polarized internal targetb CSR + AP pp elastic

II Asymmetric Collider pp 35 GeVc protons + 15 GeVc antiprotons(also fixed target experiments possible)

Towards an Asymmetric Polarized Hadron ColliderTowards an Asymmetric Polarized Hadron Collider

AATTTT for PAX kinematic conditions for PAX kinematic conditionsFixed TargetFixed Target vsvs Collider Collider

Anselmino et al PLB 59497 (2004)

22 GeVc

15+35

22 GeVc fixed target

15+35 collider

15 + 15 collider

Collider Options for Transversity measurementbull 15 GeVc + 15 GeVc s=1000 GeV2 too highbull 15 GeVc + 35 GeVc s=220 GeV2 idealideal

Similar predictions by Efremov et al Eur Phys J C35 207

(2004)

Conceptual Detector DesignConceptual Detector Design

~3 m

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

AATTTT for PAX kinematic conditions for PAX kinematic conditionsFixed TargetFixed Target vsvs Collider Collider

Anselmino et al PLB 59497 (2004)

22 GeVc

15+35

22 GeVc fixed target

15+35 collider

15 + 15 collider

Collider Options for Transversity measurementbull 15 GeVc + 15 GeVc s=1000 GeV2 too highbull 15 GeVc + 35 GeVc s=220 GeV2 idealideal

Similar predictions by Efremov et al Eur Phys J C35 207

(2004)

Conceptual Detector DesignConceptual Detector Design

~3 m

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Conceptual Detector DesignConceptual Detector Design

~3 m

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Time scheduleTime schedule

Jan 04 LOI submitted

150604 QCD PAC meeting at GSI

18-190804 Workshop on polarized antiprotons at GSI

150904 Additional PAX document on Polarization at GSIbull F Rathmann et al PRL 94 014801 (2005)

151104 Additional PAX document Number of IPrsquos at HESR211204 Additional PAX document Asymmetric Collider150105 Technical Report (with Milestones)

o Design and Construction of APR at IKP of FZJ

Evaluations amp Green Light for Construction

2005-2008 Technical Design Reports (for Milestones)

gt2012 Commissioning of HESR

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

ConclusionConclusion

Challenging opportunities and new physics accessible at HESR

bullUnique access to a wealth of new fundamental physics observables

bullCentral physics issueCentral physics issue h1q

(xQ2) of the proton in DY processes

bullOther issuesbull Electromagnetic Formfactorsbull Polarization effects in Hard and Soft Scattering processesbull differential cross sections analyzing powers spin correlation

parameters

Asymmetric Collider bull 15 GeVc + 35 GeVc

bull ideal conditions for Transversity measurementsbull Calculation of Intrabeam and Beam-Beam Scattering

(MeshkovSidorin using BETACOOL)

Projections for HESR fed by a dedicated APbull Pbeam gt 030bull 56middot1010 polarized antiprotonsbull Luminosity Fixed target L 27 middot1031 cm-2s-1

Collider L 1030 cm-2s-1 (first estimate)

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Yerevan Physics Institute Yerevan ArmeniaDepartment of Subatomic and Radiation Physics University of Gent Belgium

University of Science amp Technology of China Beijing PR ChinaDepartment of Physics Beijing PR China

Centre de Physique Theorique Ecole Polytechnique Palaiseau FranceHigh Energy Physics Institute Tbilisi State University Tbilisi GeorgiaNuclear Physics Department Tbilisi State University Tbilisi GeorgiaForschungszentrum Juumllich Institut fuumlr Kernphysik Juumllich Germany

Institut fuumlr Theoretische Physik II Ruhr Universitaumlt Bochum GermanyHelmholtz-Institut fuumlr Strahlen- und Kernphysik Bonn GermanyPhysikalisches Institut Universitaumlt Erlangen-Nuumlrnberg Germany

Unternehmensberatung und Service Buumlro (USB) Gerlinde Schulteis amp Partner GbR Langenbernsdorf GermanyDepartment of Mathematics University of Dublin Dublin Ireland

University del Piemonte Orientale and INFN Alessandria ItalyDipartimento di Fisica Universita di Cagliari and INFN Cagliari Italy

Instituto Nationale di Fisica Nucleare Ferrara Italy Dipartimento di Fisica Teorica Universita di Torino and INFN Torino Italy

Instituto Nationale di Fisica Nucleare Frascati ItalyDipartimento di Fisica Universita di Lecce and INFN Lecce Italy

Soltan Institute for Nuclear Studies Warsaw PolandPetersburg Nuclear Physics Institute Gatchina Russia

Institute for Theoretical and Experimental Physics Moscow RussiaLebedev Physical Institute Moscow Russia

Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research Dubna RussiaDzhelepov Laboratory of Nuclear Problems Joint Institute for Nuclear Research Dubna Russia

Laboratory of Particle Physics Joint Institute for Nuclear Research Dubna RussiaBudker Institute for Nuclear Physics Novosibirsk Russia

High Energy Physics Institute Protvino RussiaInstitute of Experimental Physics Slovak Academy of Sciences and PJ Safarik University Faculty of Science Kosice Slovakia

Department of Radiation Sciences Nuclear Physics Division Uppsala University Uppsala SwedenCollider Accelerator Department Brookhaven National Laboratory USA

RIKEN BNL Research Center Brookhaven National Laboratory USAUniversity of Wisconsin Madison USA

Department of Physics University of Virginia Virginia USA

~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)~170 PAX Collaborators 34 Institutions (17 inside 17 outside EU)

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

OutlineOutline

WHYWHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

TransversityTransversity

Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner

2Q

- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different evolution than - Sensitive to valence quark polarization

PropertiesProperties

q

Impossible in DIS Direct Measurement

ppl+l-X epersquohX

Indirect MeasurementConvolution with

unknown fragment fct

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Other Physics TopicsOther Physics Topics

bull Single-Spin Asymmetriesbull Electromagnetic Form Factorsbull Hard Scattering Effectsbull Soft Scattering

ndash Low-t Physicsndash Total Cross Sectionndash pbar-p interaction

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Proton Electromagnetic Formfactors Proton Electromagnetic Formfactors

bullMeasurement of relative phases of magnetic and electric FF in the time-like region

ndash Possible only via SSA in the annihilation pp rarr e+e-

bullDouble-spin asymmetryndash independent GE-Gm separationndash test of Rosenbluth separation

in the time-like region

2

p2

2E

22M

2M

E

y

m4q

|G|)(sin|G|)(cos1

)GGIm()2sin(A

τ

ττ

S Brodsky et al Phys Rev D69 (2004)

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

pp

pp

p (GeVc)

Study onset of Perturbative QCDStudy onset of Perturbative QCD

Pure Meson Landbull Meson exchangebull ∆ excitation bull NN potential models

Transition RegionbullUncharted TerritorybullHuge Spin-Effects in pp elastic scattering

bulllarge t non- and perturbative QCD

High Energybull small t Reggeon Exchangebull large t perturbative QCD

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

pp elastic scattering from ZGSpp elastic scattering from ZGS

Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))

Hard scattering takes Hard scattering takes place only with spins place only with spins

DG Crabb et al PRL 41 1257 (1978)

T=1085 GeV

Similar studies in pp elastic scattering at

PAX

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

OutlineOutline

WHY WHY Physics CasePhysics Case

HOWHOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementsTransversity Measurements

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

P beam polarizationQ target polarizationk || beam direction

σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)

polbeam

polbeam

tt

0

tt

0

ee2

I)t(I

ee2

I)t(I

τ

τ

τ

τ

transverse case

Q0tot

longitudinal case

Q)( ||0tot

For initially equally populated spin states (m=+frac12) and (m=-frac12)

revtpolpol

revtc0beam

fdQ

1

fd)(

1

τ

τ

τ

τ

τ

pol

t

0

pol

tcosheIII)t(I

ttanh

II

II)t(P

beam

Time dependence of P and I

Spin Filter MethodSpin Filter Method

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

statistical error of a double polarization observable (ATT)

NQP

1TTA

Measuring time t to

achieve a certain error

δATT ~ FOM = P2middotI

Polarization Buildup Optimum Interaction TimePolarization Buildup Optimum Interaction Time

(N ~ I)

Optimimum time forPolarization Buildup

given by maximum of FOM(t)

tfilter = 2middotτbeam

0 2 4 6 tτbeam

II 0

02

04

06

08

Beam

Pola

riza

tion

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Experimental SetupExperimental SetupResultsResults

F Rathmann et al PRL 71 1379 (1993)

T=23 MeV

Low energy pp scattering

1lt0 tot+lttot-

Expectation

Target Beam

Experimental Results from Filter TestExperimental Results from Filter Test

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

1992 Filter Test at HD-TSR with protons1992 Filter Test at HD-TSR with protons

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1

Expected build-up P(t)=tanh(tτpol)

1τpol=σ1Qdtf=24x10-2 h-1

about factor 2 larger

σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2

f = 1177 MHz

Three distinct effects

1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb

2 Small angle scattering of target protons into ring acceptance σS=52 mb

33 Spin transfer from polarized electrons of the target atoms to Spin transfer from polarized electrons of the target atoms to the stored protonsthe stored protons

σEM=70 mb (-)Horowitz amp Meyer PRL 72 3981 (1994)

HO Meyer PRE 50 1485 (1994)

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Spin Transfer from Electrons to ProtonsSpin Transfer from Electrons to Protons

epep

020

p2

ep2

EM

pa2ln2sin

2C

mp

m14

2

1

Horowitz amp Meyer PRL 72 3981 (1994)HO Meyer PRE 50 1485 (1994)

α fine structure constantλp=(g-2)2=1793 anomalous magnetic momentme mp rest massesp cm momentuma0 Bohr radiusC0

2=2πη[exp(2πη)-1] Coulomb wave functionη=zαν Coulomb parameter (negative for antiprotons)v relative lab velocity between p and ez beam charge number

EM||EM 2

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Dedicated Antiproton Polarizer (AP)Dedicated Antiproton Polarizer (AP)

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

||EM||EM Q2

Siberian Snake

B

Injection

Extraction

150 m

440 m

Polarization Buildup in AP parallel to measurement in HESR

β=02 mq=15middot1017 s-1

T=100 KLongitudinal Q (300 mT)

db=ψaccmiddotβmiddot2dt=dt(ψacc)

lb=40 cm (=2middotβ)

df=1 cm lf=15 cm

F Rathmann et al PRL 94 014801 (2005)

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Beam lifetimes in the APBeam lifetimes in the AP

10 100 1000 T (MeV)

40

30

25

ψacc(mrad)

20102

4

6

8

beam

lilf

eti

me τ

beam (

h)

10

Beam Lifetime

Coulomb Loss

Total Hadronic )T()T(

m4

)T(s1

)m4)T(s()T(s

m4)m2)T(s(4d

d

d)T(

pptot0

2p

2acc

22p

2

2p

22p2

RuthaccC

max

min

)T(f)(d))T()T((

1)T(

revacct0accCaccbeam

τ

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Optimum Beam Energies for Buildup in APOptimum Beam Energies for Buildup in AP

ψacc= 50 mrad

40 mrad

30 mrad

20 mrad

AP Space charge limit

1 10 T (MeV)100 10 mrad

FOM

5

10

15

Maximum FOM

Ψacc

(mrad)

Τbeam

(h)

P(2middotτbeam

)

T(MeV)

10 12 019 163

20 22 029 88

30 46 035 61

40 92 039 47

50 167 042 38

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Space-Charge Limitation in the APSpace-Charge Limitation in the AP

10 mrad1 10 T (MeV)100

ψacc= 50 mrad40 mrad30 mrad20 mrad10 mrad

109

1010

1011

1012

1013

Nind

Nreal

Before filtering startsNreal = 107 s-1 middot 2τbeam

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Transfer from AP to HESR and AccumulationTransfer from AP to HESR and Accumulation

e-coolere-coolerAP

HESR

ABS

Polarizer Target

InternalExperiment

Siberian Snake

B

Injection

Extraction

150 m

440 m

COSY

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

50 mrad40 mrad

30 mrad20 mrad10 mrad

20 40 60 t (h)80

4middot1010

6middot1010

8middot1010

2middot1010

0

Accumulation of Polarized Beam in HESRAccumulation of Polarized Beam in HESRPIT dt=72middot1014 atomscm2

τHESR=115 h

10

HESR2

7

p

1065

e

sp10N

τ

Number accumulated in equilibrium independent of

acceptance

Np

bar

No Depolarization in HESR during energy change

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

How about a Pure Polarized Electron TargetHow about a Pure Polarized Electron Target

1 10 100 T (MeV)

σEM

|| (

mb

)100

200

300

400

500

600

EM||EM 2

Pure Electrons

Atomic Electrons

Maxiumum σEM|| for electrons at rest (675 mb Topt = 62 MeV)Gainfactor ~15 over atomic e- in a PIT

Density of an Electron-Cooler fed by 1 mA DC polarized electrons

bullIe=62middot1015 esbullA=1 cm2

bulll=5 mdt = Iemiddotlmiddot(βmiddotcmiddotA)-1 = 52middot108 cm-2

Electron target density by factor ~106 smaller no match for a PIT (gt1014 cm-2)

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Performance of Polarized Internal TargetsPerformance of Polarized Internal Targets

PT = 0795 0033

HERMES

H Transverse Field (B=297 mT)

HERMES

Dz

Dzz

PT = 0845 plusmn 0028

Longitudinal Field (B=335 mT)

HERMES Stored Positrons PINTEX Stored Protons

H

Fast reorientation in a weak field (xyz)

Targets work very reliably (many months of stable operation)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHEREWHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

NEW Facility

bull An ldquoInternational Accelerator Facility for Beams of Ions and Antiprotonsrdquo

bullTop priority of German hadron and nuclear physics community (KHuK-report of 92002) and NuPECC

bullFavourable evaluation by highest German science

committee (ldquoWissenschaftsratrdquo in 2002)

bullFunding decision from German government in

22003 ndash staging and at least 25 foreign funding

bullto be build at GSI Darmstadt

should be finished in gt 2011 (depending on start)

FAIR(Facility for Antiproton and Ion Research)

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

FAIR ndash Prospects and ChallengesFAIR ndash Prospects and Challenges

bull FAIR is a facility which will serve a large part of the nuclear physics community (and beyond)

- Nuclear structure Radioactive beams- Dense Matter Relativistic ion beams- Hadronic Matter Antiprotons (polarized)

- Atomic physics- Plasma physics

bull FAIR will need a significant fraction of the available man-power and money in the years to come

1 Geuro 10 000 man-years = 100 ldquomanrdquo for 100 years

or (1000 x 10)

bull FAIR will have a long lead-time (construction no physics) staging (3 phases)

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)

-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

FLAIR(Facility for very Low energy

Anti-protons and fully stripped Ions)

SIS100300

HESR High Energy Storage RingPANDA (and PAX)

NESR

CR-Complex

The FAIR project at GSIThe FAIR project at GSI

50 MeV Proton Linac

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

HESR

Antiproton Production

Target

HESR (High Energy Storage Ring)bull Length 442 mbull Bρ = 50 Tmbull N = 5 x 1010 antiprotons

High luminosity modebull Luminosity = 2 x 1032 cm-2s-1

bull Δpp ~ 10-4 (stochastic-cooling)

High resolution modebull Δpp ~ 10-5 (8 MV HE e-cooling)bull Luminosity = 1031 cm-2s-1

The Antiproton FacilityThe Antiproton Facility

bullAntiproton production similar to CERN

bullProduction rate 107sec at 30 GeVbullT = 15 - 15 GeVc (22 GeV)

Gas Target and Pellet Target cooling power determines thickness

SuperFRS

NESR

CR

Beam Cooling e- andor stochastic2MV prototype e-cooling at COSY

SIS100300

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

SIS100300

Internal PAX in HESRPolarized antiprotons +

PIT

LoIlsquos for Spin Physics at FAIRLoIlsquos for Spin Physics at FAIR

External ASSIAExtracted beam on PET

(Compass-like)

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

HESR

AP+COSY

The New Polarization FacilityThe New Polarization Facility

Conceptual Design Report for FAIR did not include Spin Physics Jan rsquo04 2 Letters of Intent for Spin Physics

bull ASSIA (R Bertini)bull PAX (P Lenisa FR)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity Measurement at PAXTransversity Measurement at PAX

WHEN WHEN Time ScheduleTime Schedule

ConclusionConclusion

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Transversity in Drell-Yan processes at PAX

p pQL

Q

l+

l-Q2=M2

QT

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

)Mx(q)Mx(qe

)Mx(h)Mx(he

add

ddA

22

q

21

2q

22

q1

q

21

q1

2q

TTTT

dduuq

M invariant Massof lepton pair

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Estimated Luminosity for Double PolarizationEstimated Luminosity for Double Polarization

Polarized Internal Target in HESR

L= dt x frev x Npbar

dt = areal densityfrev = revolution frequencyNpbar = number of pbar stored in HESR

(factor gt70 in measuring time for ATT with respect to beam extracted on solid target)

tot2

7

123110514

1

e

sp10

scm1072106510861027L

Qtarget = 085Pbeam = 03σtot(15 GeV) = 50 mb

In equilibrium

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Signal EstimateSignal Estimate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

d

1) Count rate estimate

)Mx(u)Mx(u

)Mx(h)Mx(ha

dd

ddA

22

21

22

u1

21

u1

TTTT

2) Angular distribution of the asymmetry

Polarized Antiproton BeamPolarized Antiproton Beam rarr rarr Polarized Proton TargetPolarized Proton Target (both transversely polarized)

p pQL

Q

l+

l-Q2=M2

QT

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

AATTTT asymmetry angular distribution asymmetry angular distribution

)Mx(u)Mx(u

)Mx(h)Mx(haA

22

21

22

u1

21

u1

TTTT

Needs a large acceptance detector (LAD)

2cos)cos1(

sin)(a

2

2

TT

bullAsymmetry is largest for angles =90deg

bullAsymmetry varies like cos(2)

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Detector Requirements Detector Requirements

bullDrell-Yan process requires a large acceptance detectorDrell-Yan process requires a large acceptance detector

bullGood hadron rejection needed bull 102 at trigger level 104 after data analysis for single

track

bullMagnetic field Magnetic field bull Increased invariant mass resolution compared to

calorimeterbull Improved PID through Energymomentum ratiobull Separation of wrong charge combinatorial backgroundbull Toroidal Field

Zero field on axis compatible with polarized target

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

One year of data taking at 50 efficiency (180 days) ATTaTT = 03

Expected precision of the h1 measurement

Collider mode 51030 cm-2s-1 Fixed Target 271031 cm-2s-1

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Extension of the ldquosaferdquo regionExtension of the ldquosaferdquo regionDetermination of h1

q(xQ2) not confined to the bdquosafeldquo region (M gt 4 GeV)

Cross section increases by two orders from M=4 to M=3 GeV rarr Drell-Yan continuum enhances sensitivity of PAX to ATT

eeqq

qq

Jqq unknown vector coupling but same Lorentzand spinor structureas other two processes

Unknown quantities cancel in the ratios for ATT but helicity structure remains

Anselmino et alPLB 59497 (2004)

Efremov et al EurPhysJ C35207 (2004)

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

OutlineOutline

WHY WHY Physics CasePhysics Case

HOW HOW Polarized AntiprotonsPolarized Antiprotons

WHERE WHERE FAIR Project at DarmstadtFAIR Project at Darmstadt

WHATWHAT Transversity MeasurementTransversity Measurement

WHENWHEN Time ScheduleTime Schedule

ConclusionConclusion

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Final Remark

Polarization data has often been the graveyard of fashionable theories If theorists had their way they might just ban such measurements altogether out of self-protection JD Bjorken

St Croix 1987

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Measurements at COSYElectron-Proton Spin-Transfer

2005 Verification of σEM at 40 70 and 100 MeV using PIT at ANKE No additional equipment needed

bull weak transverse target guide field (10 G) Qe=Qp

bull Qp pp elastic using Spectator system

bull electron cooling at injection ANKE at 0deg

gt2006 Direct measurement of σEM|| using HERMES-like PIT at TP1

bull strong longitudinal target guide field (3 kG)

ndash needs measurement of Qe

bull Snake in Cooler Telescope (Cooler Sol + WASA Sol)ndash adiabatically switched off after filtering

ndash Qp pp elastic using Spectator system

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

bull Background higher for than for e

Background for Background for Xeepp Preliminary PYTHIA result (2109 events)

bull Background from charge conjugated mesons negligible for e

e

x1000 x100

Total background

x1000 x100

e

Origin of Background

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Andreas Lehrach - Forschungszentrum Juumllich

Methods for Polarization Preservation

bull lt 5 GeV conventional methods correcting dipoles tune jump quadrupoles Siberian snake (solenoid)

bull 5 - 20 GeV adiabatic methods partial snake (helical dipole or

solenoid) ac dipole

bull gt 20 GeV Siberian snake concept Siberian snakes (helical dipole)

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Andreas Lehrach - Forschungszentrum Juumllich

Momentum Kinetic energy

Imperfection resonance

Intrinsic resonance

GeVc GeV G yQG

1789 1082 12- 1871 1155 4 1953 1228 -4+ 2364 1605 13- 2443 1678 5 2521 1752 -3+ 2920 2129 14- 2997 2202 6 3073 2275 -2+ 3465 2652 15- 3541 2725 7 3617 2798 -1+ 4005 3175 16- 4080 3248 8

14172 13265 19+ 14550 13642 36- 14624 13715 28 14697 13789 20+

Depolarizing Resonances in the HESR

Resonance strength

10-6 - 10-2Qy = 814

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Andreas Lehrach - Forschungszentrum Juumllich

AP ~1 Tm solenoidCOSY handled already

HESR 4 helical dipoles (25 Tesla)

+ 15 Tm solenoid Other Equipment

several polarimeters1 spin flipper for HESR (AC dipole)

Polarization Preservation at FAIR

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Andreas Lehrach - Forschungszentrum Juumllich

Siberian Snake for HESR

4 helical dipoles (25 Tesla) and a 15 Tm solenoid

Helical snake

Helical + solenoidal snake

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Andreas Lehrach - Forschungszentrum Juumllich

Magnetic Field Orbit and Spin

Helical dipoles

Solenoid

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

APRe-Cooler

Target

Injection Septum

Snake

RF

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

HESR Accelerator Complex with Polarized Antiprotons

Polarimeter

HESR 15-15 GeVc

COSY-Booster

30 MeV Linac

Snake protonsantiprotons

AP

Natural extension 15 GeV + 15 GeV pbarp Collider

(Spin-gymnastics)

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Double Polarization Experiments Double Polarization Experiments Azimuthal Azimuthal SymmetrySymmetry

(8 coil system under study)

bull 800 x 600 mm coils

bull 3 x 50 mm section (1450 Amm2)

bull average integrated field 06 Tm

bull free acceptance gt 80

Superconducting target field coils do not affect azimuthal acceptance

Possible solution Toroid (6 superconducting coils)Possible solution Toroid (6 superconducting coils)

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

BackgroundBackground

mbpp

50

nbDY 1 108-109 rejection factor against background

bull DY pairs can have non-zero transverse momentum (ltpTgt = 05 GeV)

coplanarity cut between DY and beam not applicable

bull Larger Background in Forward Direction (where asymmetry is smaller)

bull Background higher for than for e (meson decay)

hadronic absorber (needed for inhibits other reactions

bullSensitivity to charge avoids background from wrong-charge DY-pairs

Magnetic field envisaged

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Dream Option Collider (15 GeV)Dream Option Collider (15 GeV)

L gt 1030cm-2s-1 to get comparable rates

Mgt4 GeV

Mgt2 GeV

___ 22 GeV

___ Collider (15 GeV+15GeV)

22 GeV15 GeVCollider 15 GeV+15 GeV

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Theoretical predictionTheoretical prediction

015

02

025TT

TT

a

A

T=22 GeV

T=15 GeV

03

0 06xF=x1-x2

0402

Magnitude of Asymmetry

Angular modulation

Forward Part (FWD) lab lt 8deg

Large Acceptance Part (LAD) 8deg lt lab lt 50deg

Beam and Target PolarizationP=Q=1

LAD

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Estimated signalEstimated signalbull 120k event sample

bull 60 days at L=21 1031 cm2 s-2 P = 03 Q = 085

Events under Jy can double the statistics Good momentum resolution

required

LAD

LAD

ATT=(4304)middot10-2

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Participating Institutions Dzhelepov Laboratory of Nuclear Problems JINR Dubna Russia

Dipartimento di Fisica ldquoA Avogadrordquo and INFN Torino Italy Dipartimento di Fisica Teorica and INFN Torino Italy

Universita and INFN Brescia ItalyCzech Technical Universiy Prague Czech Republic

Charles University Prague Czech Republic DAPNIA CEN Saclay France

Institute of Scientific Instruments Academy of Sciences Brno Czech Republic

NSC Kharkov Physical Technical Institute Kharkov UkraineLaboratoi Nazionali Frascati INFN Italy

Universita dellrsquo Insubria Como and INFN Italy University of Trieste and INFN Trieste Italy

ASSIA CollaborationASSIA Collaboration Spokesperson Spokesperson Raimondo BertiniRaimondo Bertini

bertinitoinfnitbertinitoinfnit

92 Collaborators 12 Institutions (10 EU 2 outside EU)92 Collaborators 12 Institutions (10 EU 2 outside EU)

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Andreas Lehrach - Forschungszentrum Juumllich

Depolarizing Resonances in the HESR

bull Imperfection 25 4 5 6 28

Strong 8 16 24

bull Intrinsic50

-4+ -3+ 20+

12- 13- 35-

Strong 0+ 8+ 12+ 16+ 24- 32+ 36-

bull Coupling50

-4+ -3+ 20+

12- 13- 36-

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Background for Background for Xeepp

Average multiplicity 4 charged + 2 neutral particle per event

Combinatorial background from meson decay

Estimate shows for most processes background under control

pp21hh X

eeK 0

ee0

eeK 0

ee

ee

21hh

hellip

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate

Drell-Yan cross section and event rateDrell-Yan cross section and event rate

q

22

21

22

21

2q

212

2

F2

2

MxqMxqMxqMxqe)xx(sM9

4

dxdM

dbullM2 = s x1x2 bullxF=2QLradics = x1-x2

bull Mandatory use of the invariant mass region below the J (2 to 3 GeV)

bull 22 GeV preferable to 15 GeV

bullx1x2 = M2s

15 GeV22 GeV

Mgt2 GeV

Mgt4 GeV

22 GeV

15 GeV

M (GeVc2)

2 k eventsday

• Folie 1
• Central Physics Issue
• Folie 3
• Evaluation by QCD Program Advisory Committee (July 2004)
• Folie 5
• Folie 6
• Folie 7
• Folie 8
• Folie 9
• Folie 10
• Folie 11
• Folie 12
• Folie 13
• Folie 14
• Folie 15
• Folie 16
• Folie 17
• Outline
• Folie 19
• Folie 20
• Proton Electromagnetic Formfactors
• Study onset of Perturbative QCD
• pp elastic scattering from ZGS
• Slide 24
• Folie 25
• Folie 26
• Experimental Results from Filter Test
• Folie 28
• Folie 29
• Folie 30
• Folie 31
• Folie 32
• Folie 33
• Folie 34
• Folie 35
• Folie 36
• Folie 37
• Folie 38
• Slide 39
• Folie 40
• Folie 41
• Folie 42
• Folie 43
• Folie 44
• Folie 45
• Folie 46
• Slide 47
• Folie 48
• Folie 49
• Signal Estimate
• ATT asymmetry angular distribution
• Folie 52
• Folie 53
• Extension of the ldquosaferdquo region
• Slide 55
• Folie 56
• Measurements at COSY Electron-Proton Spin-Transfer
• Folie 58
• Folie 59
• Methods for Polarization Preservation
• Depolarizing Resonances in the HESR
• Folie 62
• Siberian Snake for HESR
• Magnetic Field Orbit and Spin
• Folie 65
• HESR Accelerator Complex with Polarized Antiprotons
• Folie 67
• Folie 68
• Folie 69
• Folie 70
• Folie 71
• Folie 72
• Slide 73
• Folie 74
• Drell-Yan cross section and event rate