physics with a neutrino factory complex

CHIPP-NU Neuchatel Alain Blondel, 21/6/04

Physics with a Neutrino Factory Complex

-- Principles

-- performance

-- other physics and muon collider

-- R&D in Europe and elsewhere

This summarizes the work of several 100 authors whorecently published 'ECFA/CERN studies of a European Neutrino Factory Complex'CERN 2004-002ECFA/04/230and of the US-based Muon Collaboration (S. Geer & R. Palmer et al)


-- Neutrino Factory --CERN layout

e+ e

_

interacts

giving

oscillates e

interacts giving

WRONG SIGN MUON

1016p/s

1.2 1014 s =1.2 1021 yr

3 1020 eyr

3 1020 yr

0.9 1021 yr


Detector

Iron calorimeter Magnetized

Charge discrimination B = 1 T

R = 10 m, L = 20 m Fiducial mass = 40 kT

Baseline

3500 Km

732 Km 3.5 x 107

1.2 x 106

5.9 x 107

2.4 x 106

1.1 x 105

1.0 x 105

CC e CC signal (sin2 13=0.01)

Events for 1 year

Also: L Arg detector: magnetized ICARUS Wrong sign muons, electrons, taus and NC evts *->

CF e signalat J-PARC=40

4Oscillation parameters can be extracted using energy distributions

a) right-sign muonsb) wrong-sign muonsc) electrons/positronsd) positive -leptonse) negative -leptonsf) no leptons

X2 (+ stored and - stored) Eve

nts

Bueno, C

am

pan

elli, R

ubb

ia; h

ep-p

h/0

00500

07

Simulated distributions for a 10kt LAr detectorat L = 7400 km from a 30 GeV nu-factory with

1021 + decays.

EVIS (GeV)

Note: e is specially important(Ambiguity resolution & Unitarity test): Gomez-Cadenas et al.


Linder et al.

Above plot obtained with Golden channel, one sign only and one distance.Emphasizes very low systematics, and degeneracies


Neutrino fluxes + -> e+ e

/ e ratio reversed by switching

e spectra are different No high energy tail.

Very well known flux (aim is 10-3)

- absolute flux measured from muon current or by e -> e in near expt.

-- in triangle ring, muon polarization precesses and averages out (preferred, -> calib of energy, energy spread)

-- E& calibration from muon spin precession

-- angular divergence: small effect if < 0.2/can be monitored

-- in Bow-tie ring, muon polarization stays constant, no precession 20% easy -> 40% hard Must be measured!!!! (precision?) Physics gain not large

polarization controls e flux:

+ -X> e in forward direction


CP asymmetriescompare e to e probabilities

e

_

e-

e

_

e-

//

// A

is prop matter density, positive for neutrinos, negative for antineutrinos

HUGE effect for distance around 6000 km!! Resonance around 12 GeV when

m223 cos213 =

0


CP violation (ctd)

Matter effect must be subtracted. One believes this can be done with uncertaintyOf order 2%. Also spectrum of matter effect and CP violation is differentIt is important to subtract in bins of measured energy. knowledge of spectrum is essential here!

5-10 GeV

10-20 GeV20-30 GeV

30-40 GeV40-50 GeV

40 kton L M D 50 GeV nufact5 yrs 1021/yr

In fact, 20-30 GeV Is enough!

Best distance is 2500-3500 km

e.g. Fermilab or BNL-> west coast or …


Bueno, Campanelli, Rubbia hep-ph/0005-007


e.g. Rigolin, Donini, Meloni


channel at neutrino factory

High energy neutrinos at NuFact allow observation of e(wrong sign muons with missing energy and P). UNIQUE

Liquid Argon or OPERA-like detector at 732 or 3000 km.

Since the sin dependence has opposite sign with the wrong sign muons, this solves ambiguitiesthat will invariably appear if only wrong sign muons are used.

ambiguities with only wrong sign muons (3500 km)

equal event number curvesmuon vs taus

associating taus to muons (no efficencies, but only OPERA mass)

studies on-going

A. Donini et al


Wrong sign muons alone

Wrong sign muons and taus

Wrong sign muons and taus + previous exp.


red vs blue = different baselines

dashed vs line = different energy bin (most powerful is around matter resonance @ ~12 GeV)

red vs blue = muons and taus


Conclusion:

Neutrino Factory has many handles on the problem (muon sign + Gold + Silver + different baselines + binning in energy )thanks to high energy!"It could in principle solve many of the clones for down to 10

The most difficult one is the octant clone which will require a dedicated analysis" (Rigolin)


Where will this get us…

comparison of reach in the oscillationsright to left:present limit from the CHOOZ experiment, expected sensitivity from the MINOS experiment, CNGS (OPERA+ICARUS)0.75 MW JHF to super Kamiokande with an off-axis narrow-band beam, Superbeam: 4 MW CERN-SPL to a 400 kt water Cerenkov@ Fréjus (J-PARC phase II similar)Neutrino Factory with 40 kton large magnetic detector.

0.10 10 2.50 50 130

Mezzetto

X 5


Superbeam onlyBeta-beam only

Betabeam + superbeam

3 sigma sensitivity of various options

NUFACT


Could begin as soon as SPL/accumulator is build:

-High intensity low energy muon experiments -- rare muon decays and muon conversion (lepton Flavor violation) -- GF, g-2, edm, muonic atoms, e+ e-

--> design of target stations and beamlines needed. - 2d generation ISOLDE (Radioactive nuclei) -- extend understanding of nuclei outside valley of stability -- muonic atoms with rare nuclei(?)

if a sufficient fraction of the protons can be accelerated to E>15 GeV:-High intensity hadron experiments -- rare K decays (e.g.K-> )

In parallel to long baseline neutrino experiments:-short baseline neutrino experiments (standard fluxes X104) -- DIS on various materials and targets, charm production

-- NC/CC -> mw (10-20 MeV) e e & ee ee -> sin2weff (2.10-4)

--> design of beamline + detectors needed

Other physics opportunities at a -factory complex

Related to high intensity


From neutrino factory to Higgs collider

h (115) Upgrade to 57.5 GeV

Separate & , add transfer lines

More cooling + E/E reduction

Muon collider: a small…. but dfficult ring


muon collider……

can do everything an electron-positron collider can do, but with

+ a very small energy spread (10-4 or better)and extremely well known energy.

++ the coupling to Higgs bosons is proportional to ml2

i.e. it is 4 104 higher for muons than electrons

-- Problem with neutrino radiation background for E> 3 TeV

-- need very large cooling factor!


Higgs factory h(115)

- S-channel production of Higgs is unique feature of Muon collider- no beamstrahlung or Synch. Rad., g-2 precession

=> outstanding energy calibration (OK) and resolution R=E/E (needs ideas and R&D, however!)

mh=0.1 MeVh=0.3 MeVh->bb /h = 1%

very stringent constraints onHiggs couplings (b)


Higgs Factory #2: H, A

SUSY and 2DHM predict two neutral heavy Higgs with masses close to each other and to the

charged Higgs, with different CP number, and decay modes. Cross-sections are large. Determine masses & widths to high precision.

Telling H from A: bb and tt cross-sections(also: hh, WW, ZZ…..)

investigate CP violating H/A interference.


Neutrino Factory studies and R&D

USA, Europe, Japan have each their scheme. Only one has been costed, US study II:

Neutrino Factory CAN be done…..but it is too expensive as is. Aim: ascertain challenges can be met + cut cost in half.

+ detector: MINOS * 10 = about 300 M€ or M$

Neutrino Factory Concept - 1

25

1. Make as many charged pions as possible INTENSE PROTON SOURCE

(In practice this seems to mean one with a beam power of 4 MW)

2. Capture as many charged pions as possible Low energy pionsGood pion capture scheme

3. Capture as many daughter muons as possible within an acceleratorReduce phase-space occupied by the s Muon cooling

4. Accelerate FAST!

Example: US Design Study 2

NB. Energy of proton source not so relevant 2-50 GeV considered

Neutrino Factory Concept - 226

UK DesignFast cycling synchrotron Japanese Design

J-PARC based


MUTAC ( 14-15 jan 2003)(US) The committee remains convinced that this experiment, which is absolutely required tovalidate the concept of ionization cooling, and the R&D leading to it should be thehighest priority of the muon collaboration. Planning and design for the experiment haveadvanced dramatically(…)

EMCOG: (6 feb 2003) (Europe)(…)EMCOG was impressed by the quality of the experiment, which has been well studied, is well organized and well structured. The issue of ionization cooling is critical and this justifies the important effort that the experiment represents. EMCOG recommends very strongly a timely realization of MICE.

MUTAC: Muon Technical Advisory Committee (Helen Edwards, et al) (US)EMCOG: European Muon Coordination and Oversight Group (C. Wyss et al)

ECFA recommendations (September 2001:)

28

Why we are optimistic/enthusiastic – US perspective:

We are working towards a “World Design Study” with an emphasis on cost reduction.

Note: In the Study 2 design roughly ¾ of the cost came from these 3 roughly equally expensive sub-systems.

New design has similar performance to Study 2 performance but keeps both + and - !

S. Geer:

Good hope for improvement in performance ad reduction of cost!


The four priorities set up by EMCOG (European Muon Coordination and Oversight Group)

-- High intensity proton driver (SPL; etc..)-- High power target -- high rep rate collection system (horns, solenoid)-- Ionization coolng demonstration

These will correspond to the workpackages of the ECFA/ESGARD superbeam/neutrino factory feasibility study

0 T

10 T

20 T

Targetry: The Study 2 Design used a 20 m/s Hg Jet in a 20 T Solenoid

30

• 1cm diameter Hg Jet• V = 2.5 m/s • 24 GeV 4 TP Proton Beam• No Magnetic Field

BNL E951 Hg Jet Tests CERN/Grenoble Hg Jet Tests

• 4 mm diameter Hg Jet

• v = 12 m/s

• No Proton Beam

Targetry: Proposal to test a 10m/s Hg Jet in a 15T Solenoid with an Intense Proton Beam

31

Muon Collaboration

Participating Institutions1) RAL2) CERN3) KEK4) BNL5) ORNL6) Princeton University

Note: The solenoid is under construction, and the Hg-jet under development.


The HARP experimentThe HARP experiment

124 people 24 institutes

Spectrometer resolution


HORN STUDIES First prototype ready

Thanks to the CERN Workshop

S. Gilardoni


IONIZATION COOLING

Difficulty: affordable prototype of cooling section only cools beam by 10%, while standard emittance measurements barely achieve this precision.Solution: measure the beam particle-by-particle

A delicate technology and integration problem Need to build a realistic prototype and verify that it works (i.e. cools a beam)Difficulties lay in particular in operating RF cavities in Mag. Field, interface with SC magnets and LH2 absorbers What performance can one get?

principle:

this will surely work..!

reality (simplified)

….maybe…

state-of-the-art particle physics instrumentation will test state-of-the-art accelerator technology.

RF Noise!!

Ionization Cooling - MUCOOL

35

5T Cooling ChannelSolenoid – LBNL

& Open Cell NCRF Cavity operated at

Lab G – FNAL

Thin absorber windowsTested – new technique

– ICAR Universities201 MHz half-shell ebeam welding of Stiffening – JLab

New MUCOOL Test Area Completed – FNAL

LH2 Absorber Cryostat– KEK

MICE – The International Muon Ionization Cooling Experiment36

Build & operate a section of a realistic cooling channel & measure its performance in a muon beam (at RAL) for various operation modes & beam conditions.

Experiment is approved at RAL. (~10.-12.5 M£ earmarked in UK) under discussion with funding agencies.


Incoming muon beam

Diffusers 1&2

Beam PIDTOF 0

CherenkovTOF 1

Trackers 1 & 2 measurement of emittance in and out

Liquid Hydrogen absorbers 1,2,3

Downstreamparticle ID:

TOF 2 Cherenkov

Calorimeter

RF cavities 1 RF cavities 2

Spectrometer solenoid 1

Matching coils 1&2

Focus coils 1 Spectrometer solenoid 2

Coupling Coils 1&2

Focus coils 2 Focus coils 3Matching coils 1&2

10% cooling of 200 MeV/c muons requires ~ 20 MV of RF single particle measurements =>

measurement precision can be as good as out/ in ) = 10-3

never done before either….


Responsibilities as proposed in the proposal (Hardware) (conditional to approval by funding agencies)

Belgium Downstream Cherenkov

Netherlands Magnetic probes and measurement

INFN Spectrometer solenoid, TOF detectors,Calorimeter, Tracker, DAQ

Switzerland Beam Solenoid (PSI), Tracker

CERN Refurbished RF power sources

UK Beam, Home and Infrastructure!Focus coils, Absorber, Tracker

Russia under discussions

Japan Absorbers tracker

USA RF cavities, coupling coil Absorbers tracker up-and downstream Cherenkov

Acceleration

39

Muon CollaborationMuch progress in Japan with the development and demonstrationof large acceptance FFAGaccelerators.

Latest ideas in US have lead tothe invention of a new type of FFAG (so-called non-scaling FFAG) which is interesting formore than just Neutrino Factories,& may require a demonstrationexperiment (plans are developing).

Perhaps US & Japanese conceptsare merging to produce something better ??

New US Acceleration Scheme … still evolving


APEC design study (sub ?)

SPL Superbeam Neutrino factoryThe ultimate tool for neutrino oscillations

Beta beam Very large underground labWater Cerenkov, Liq.ArgEURISOL

SPL physics workshop: 25-26-27 May 2004 at CERN CERN SPSC Cogne meeting sept. 2004

Superbeam/neutrino Factory design study (sub ?)

EURISOL design study (sub 2004 --successful)

HIPPI


Conclusions

1. the Neutrino Factory remains the most powerful tool imagined so far to study neutrino oscillations

High energy e and etransitions

2. The complex offers many other possibilities

3. It is a step towards muon colliders

4. There are good hopes to reduce the cost significantly

5. Regional and International R&D o components and R&D experiments are being performed by an enthusiastic and motivated community 6. Opportunities exist in Europe: HI proton driver, Target experiment @ CERN Collector development @LAL-CERNMICE @ RAL

physics with a neutrino factory complex

Documents

neutrino factories

apec design study sub

eurisol design study

cern collector development

new us acceleration

cern cern spsc cogne

coil absorbers tracker

us japanese conceptsare