experiment at fair compressed baryonic matter
DESCRIPTION
Experiment at FAIR Compressed Baryonic Matter Exploring Phase Diagram of strongly Interacting Matter using High Energy Heavy Ion Collisions Subhasis Chattopadhyay, VECC. OUTLINE. Why high energy heavy ion experiment at FAIR important? CBM experiment Why should we participate? - PowerPoint PPT PresentationTRANSCRIPT
Experiment at FAIR
Compressed Baryonic Matter
Exploring Phase Diagram of strongly Interacting Matter using
High Energy Heavy Ion Collisions
Subhasis Chattopadhyay, VECC
•Why high energy heavy ion experiment at FAIR important?
•CBM experiment
•Why should we participate?
•How should we participate?
•Travel so far..
•RoadMap
OUTLINEOUTLINE
States of strongly interacting matter
baryons hadrons partons
Compression + heating = quark-gluon matter (pion production)
Neutron stars Early universe
Phase Diagram from cartoon to precise
Tool: High energy heavy ion collisions, generate density/temparature
Quark Gluon Plasma(the definition)
When the energy density exceeds some typical hadronic value (~1 GeV/fm^3), matter no longer consists of separate hadrons (protons, neutrons etc.), but as their fundamental constituents, quarks and gluons. Because of the apparent analogy with similar phenomena in atomic physics we may call this phase of matter the QCD (or quark-gluon) plasma. : PHENIX white paper
QGP=a (locally) thermally equilibrated state of matter in which quarks and gluons are deconfined from hadrons, so that color degrees of freedom become manifest over nuclear, rather than merely nucleonic, volumes. Not required: Non interacting quarks and gluons : Chiral symmetry restored : 1st or 2nd order phase transition : STAR white paper
timelineCourtesy of S. Bass
correlations:(1) thermalization?(2) is there conical
flow?
elliptic flow:(1) does hydro work?(2) what EOS?
hadronshadronic scatterings
freeze-out
1 2 3Initial condition: CGC
high-Q2 interactions
medium formation
hot, dense medium
expansion
hadronization
ratios, spectra:freeze-out propertiesfluctuations, etc.
SPS to RHIC : journey continuing…Observations:
SPS• Matter is different than ordinary nuclear matter, needs different treatment..• Some smoking gun signatures (J/Psi suppression) exist• Not all signatures gave smoke.RHIC:
•The matter is extremely dense and it thermalizes very rapidly.• Estimates of the energy density (10-15 GeV/fm^3) well in excess of the density needed for a QGP predicted by LQCD• Matter seems to be strongly interacting with no viscosityButNeed to have (unequivocal) evidence that
•matter is deconfined•Order of Phase Transition (Cross-over)?
Our journey: SPS@CERN
2cm x 2cm scintillator 8000 cells WA93(data taken: 1991)
52000 cells, WA98(Data taken: 1993-1996)
STAR experiment at RHIC, BNL
Our understanding so farQuick glimpses
Leading hadron suppression
-
Wang and Gyulassy: E softening of fragmentation suppression of leading hadron yield
ddpdT
ddpNdpR
TNN
AA
TAA
TAA /
/)(
2
2
Ivan Vitev, QM02
Inclusive yield relative to binary-scaled p+p
Suppression of the inclusive yield in central Au+Au is a final-state effect
• d+Au : enhancement Au+Au: strong suppression
• pT=4 GeV/c: cent/minbias = 1.110.03 central collisions enhanced wrt minbias
ddpdT
ddpdNR
Tpp
AB
TAB
AB /
/
Azimuthal distributions
pedestal and flow subtracted
Near-side: p+p, d+Au, Au+Au similarBack-to-back: Au+Au strongly suppressed relative to p+p and d+Au
Suppression of the back-to-back correlation in central Au+Au is a final-
state effect
Suppression of away-side jet consistent with strong absorption in bulk, emission dominantly from surface
?
15
A related question: the initial condition
• Large nucleus (A) at low momentum fraction x gluon distribution saturates ~ 1/s(QS
2) with QS2 ~ A1/3
• A collision puts these gluons ‘on-shell’ ~ A xg(x,Q2) / R2
• Parton-hadron maps gluons directly to charged hadrons
• Parton dynamics in a dense system of gluons differs from pQCD
• Saturated gluon density ( CGC ) effective field theory of dense gluon systems provides an appropriate description of the initial condition
D. Kharzeev, E. Levin and L. McLerran, Phys. Lett. B 561 (2003) 93
Highlight of the first paper from STAR PMD
First time in Heavy-Ion collisions we showed that photons and pions follow energy independent limiting fragmentation.
We have resolved the contradictory results (from two contemporary experiments at RHIC) on the impact parameter dependence of limiting fragmentation of charged particles.
What have we learned (so far)?
+The matter is extremely dense and it thermalizes very rapidly. First order estimates of the energy density all well in excess of the density needed for a QGP predicted by LQCD (~ 10-15 GeV/fm3).
But– Need to have (unequivocal) evidence that
• the matter is deconfined• Order of Phase Transition (Cross-over)?• sQGP (strongly interacting) with no viscosity
What have we learned (so far)?• Demand an explanation beyond a purely hadronic scenario:
– The hydro-models require early thermalization (therm< 1fm/c) and high initial energy density > 10 GeV/fm3
– Implies the matter is well described as ideal relativistic fluid
– Initial gluon density dng/dy~1000 and initial energy density e~15 GeV/fm3 are obtained model of jet quenching.
• Estimates of energy density are well in excess of ~1 GeV/fm3 obtained in lattice QCD as the energy density needed to form a deconfined phase.
Meanwhile, SPS people have started looking at Their data again…
Interestingly, many RHIC observations are reproduced and then new ones..
Make more precision measurement at SPS energies. Only Hadronic observables..
The Kink
Van-Hove
Fluctuation
one more speculation ....
coexistence phase
hadronsQGP
critical point
ENERGY SCAN….ENERGY SCAN….
In fact, energy scan is done....RHIC
What has not been done:
Looking in extreme detail at lower energies.Effort was to get hot QGP, so only few global observables were studied.
No rare probe search (Heavy flavor, pre-thermal photons etc)Some effort started at SPS, but that too at 1-2 beam energies.
After RHIC people started talking about low energy RHIC run,
(Reanalyzed SPS data are finding that they have also found what RHIC is finding today, even jet-quenching..)
Arguments being given are..
Exploring the QCD Phase-diagram
Matter Density μB (GeV)
Tem
per
atu
re (
MeV
)
Quark-Gluon Plasma
Hadron Gas
Phase Boundary
0
200
0
Atomic Nuclei
1
Critical Point
Susceptibilities diverge near critical point
Locate the critical point using correlation/fluctuation measurements
√s
<(X - <X>)2> Enhanced Fluctuationsnear Critical Point
Rajagopal, Shuryak,Stephanov
Critical Point
Matter Density μB (GeV)
Tem
per
atu
re (
MeV
)
Quark-Gluon Plasma
Hadron Gas
Phase Boundary
0
200
0
Atomic Nuclei
1
Critical Point
Exploring the QCD Phasediagram
Plot from M. Stephanov, Correlations ‘05
Challenge: Guidance on exact location and strength of correlation signals is limited
QCD Phase Diagram
Model predictions:
1) All ‘end points’ exist at B > 0.1GeV
2) Most ‘end points’ exist at B < 0.95GeV
3) Large uncertainties in the predictions. Data is important.
M.A Stephanov, Prog. Theor. Phys. Suppl. 153, 139(2004); Int. J. Mod.
Phys. A20, 4387(05); hep-ph/0402115
pn
++
K
p
e+
e-
Looking into the fireball …
… using penetrating probes:
short-lived vector mesons decaying into electron-positron pairs
SIS18 SIS100/
300
Meson production in central Au+Au collisionsW. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl. Phys. A 691 (2001) 745
We must go back to low energy DETAILED measurements
Understand QCD at high baryon density Critical point and phase transition (critical fluctuations) Chiral Phase transition (Mass modifications) Neutron STAR (strange matter at high baryon density).
The phase diagram of strongly interacting matter(Revisit)
RHIC, LHC: high temperature, low baryon densityFAIR: moderate temperature, high baryon density
Baryon density in central cell (Au+Au, b=0 fm): HSD: mean field, hadrons + resonances + strings QGSM: Cascade, hadrons + resonances + strings
Transport calculations: energy densities
C. Fuchs, E. Bratkovskaya, W. Cassing
Baryon density in central cell (Au+Au, b=0 fm): HSD: mean field, hadrons + resonances + strings QGSM: Cascade, hadrons + resonances + strings
C. Fuchs, E. Bratkovskaya, W. Cassing
Transport calculations: baryon densities
SIS 100 Tm
SIS 300 Tm
Structure of Nuclei far from Stability
cooled antiproton beam:Hadron Spectroscopy
Compressed Baryonic Matter
The future Facility for Antiproton an Ion Research (FAIR)
Ion and Laser Induced Plasmas:
High Energy Density in Matter
low-energy antiproton beam:antihydrogen
Primary beams:1012 /s 238U28+ 1-2 AGeV4·1013/s Protons 90 GeV1010/s U 35 AGeV (Ni 45 AGeV)
Secondary beams:rare isotopes 1-2 AGeVantiprotons up to 30 GeV
Observables:Penetrating probes: , , , J/ (vector mesons)Strangeness: K, , , , , Open charm: Do, D
Hadrons ( p, π), exotica
Experimental program of CBM:
Systematic investigations:A+A collisions from 8 to 45 (35) AGeV, Z/A=0.5 (0.4) p+A collisions from 8 to 90 GeVp+p collisions from 8 to 90 GeVBeam energies up to 8 AGeV: HADES
Large integrated luminosity:High beam intensity and duty cycle,Available for several month per year
Detector requirementsLarge geometrical acceptance good particle identificationexcellent vertex resolutionhigh rate capability of detectors, FEE and DAQ
Compressed Baryonic Matter: physics topics and observables
Search for chiral symmetry restoration at high B
in-medium modifications of hadrons
Observables: , ,
Search for a deconfined phase at high B enhanced strangeness production ? Observables: K, , , , anomalous charmonium suppression ? Observables: charmonium (J/ψ, ψ'), open charm (D0, D)
Probing the equation-of-state at high B
Observables: collective flow of hadrons, particle production at threshold energies (open charm)
Search for the 1. order phase transition & its critical endpoint Observable: event-by-event fluctuations (K/π, pT, ...)
Radiation hard Silicon (pixel/strip) Tracking System in a magnetic dipole field
Electron detectors: RICH & TRD & ECAL: pion suppression better 104
Hadron identification: TOF-RPC
Measurement of photons, π, η, and muons: electromagn. calorimeter (ECAL)
High speed data acquisition and trigger system
The CBM Experiment
Silicon Tracking System (STS)
Our Achievements So far…
(1) PMDs for WA93,WA98, STAR,ALICE, Muon chambers for ALICE
(2) Development of advanced gaseous detector laboratory * Gaseous detector laboratory exist at VECC-SINP and other
collaborating institutes (3) Development of advanced electronics laboratories (MANAS development, a highlight)
(4) Development of large scale computing facilities (Grid computing) (5) Successful International and National Collabotation (VECC,SINP,PU,RU,JU,IOP,AMU,IIT-Bombay)
(6) More than 40 PhD students
Future based on this strong base of experience and expertiseFuture based on this strong base of experience and expertise
Intermediate mass dimuons in p-A collisions• The p-A data is properly described by a superposition of Drell-Yan and DD decays
• The required charm cross-section is consistent with previous direct measurements
_
NA50
From NA50 to NA60 (1996 - 2000)
Improved measurement of prompt dimuon production and
open charm in heavy ion collisions
Let’s add silicon detectors to track the muons before they traverse the hadron absorber
Our ProposalBased on our experience, Aim is to take part SIGNIFICANTLY
• Work with latest detector technology• Application of the expertise in detector development in other fields.
Design, simulate, build and operate complete Muon program
Serious talk started Feb’05 during ICPAQGP, requested for good project. Asked to explore Muon option
42
Detector ChoiceDetector Choice
Silicon Tracker+ Magnet
Muon Absorber + muon stations (Proposed: Mostly Indian effort)
TOF will be placed/absorber will be removed
CBM Much Version - 1
Carbon absorberDetector layers
STSTarget 1200300
50 100 150
Gap between two detector layers = 45
Gap between absorber and adjacent detector layer = 1
Thickness of each detector layer = 10
All dimensions in mm
Study of μ ID system with absorber for CBM
C/Fe absorbers + detector layers
Simulations Au+Au 25 AGeV:
track reconstruction from hits in STS and muon chambers (100 μm position resolution)
muon ID: tracks from STS to muon chamber behind absorber
vector meson multiplicities from HSD transport code
J/ψ→μ+μ-
s/b ~ 100
ρ φω
Much version CV1 CV2 CV3 CV4 CV5Reconstructed Muon tracks (%) from decay
83 58 85 62 83
Reconstructed Muon tracks (%) from J/psidecay
94 91 95 93 95
Absorber thickness in mm.
50,100,200,300,1200 =
1850
150,300,600,900,1200 =
3450
50,100,200,300,1200 =
1850
150,300,600,900,1200 =
3450
300,400,500,650 =
1850
# of detector layers
163 detectors
between absorbers
16 3 detectors
between absorbers
11 2 detectors
between absorbers
112 detectors
between absorbers
13 3 detectors
between absorbers
Reconstruction efficiency of muon tracks through Much only without background
47
Muon Chambers:
Design parameters and method....
•Should be able to handle highest rate
•Should have good position resolution
•Should be possible to make in large area
•FEE connections and taking them out is a concern..
49
Comparison of detectors..
MWPC GEM Micromegas
Rate capability 10^6Hz/cm^2 >5x10^7Hz/cm^2 10^8Hz/cm^2
Gain High 10^6 low 10^3 (single)
> 10^5 (multi GEM)
High > 10^5
Gain stability Drops at 10^4Hz/mm^2
Stable over 5*10^5Hz/mm^2
Stable over 10^6Hz/mm^2
2D Readout ? Not really Yes and flexible Yes, not flexible
Position resolution > 200 µm (analog) 50 µm (analog) Good < 80 µm
Time resolution ~ 100 µs < 100 ns < 100 ns
Magnetic Field effect High Low Low
Cost Expensive, fragile Cheap, robust Cheap, robust
Both GEM & MICROMEGAS are suitable for high rate applications
50
Design concepts..
Wheel type design of planes with 8 sector type chambers in each plane
Each sector with a single woven mesh supported on insulating pillars - - - mechanical problems??
Readout pad granularity to vary from 3mm to 7mm pads radially in 3 zones - to keep occupancy within 10% level
(needs further optimization study)
•VECC-GSI MOU Signed
•Ongoing work by FAIR-utilization committee• (CDR in two months)
•DST-FAIR MOU to be renewed on 24th July’06
•Proposal given by VECC-IOP in XIth plan
•Included as Mega-science project
•Meeting with Secy-DST
• Detailed meeting in October
DAE-Vision on radiation Detector (2004)DAE-Vision on radiation Detector (2004)
Radiation Detector
Quest of knowledgeNeed of Society
NP, HEP, S S Physics experiments
Medical Imaging
High Density Matter (CBM)Neutrino observations (INO)
Detector Vision: need of the society
Common theme: need of the society.Medical diagonesis. X-Ray imaging: GEM, a-Si-films with scintillators, PSDs . PET: RPC
2-D Dosimetry: GEM, RPC.
Worldwide in large accelerator centres dedicated facilities are being built for development of detectors for medical applications eg. Medpix@CERN. Our experience in working with high resolution detector can be used for medical applications.
9 keV absorption radiography using GEM
Precision radiography setup using Si.
PLAN:
Full R&D in XIth plan period30% production cost
R&D (parallel effort on GEM and Micromegas)
•Dedicated Gas detector Lab•Dedicated Electronics Lab with all purpose DAQ system
•ASIC-development
Conclusion
•CBM is complementary to RHIC/LHC•Will address some fundamental questions of QCD
•We propose to take lead role in the experiment
•Experience of developing most advanced detector will help to use them in other areas.
„The challenge for the next century physics is: explain confinement and broken (chiral) symmetry“T.D. LeeT.D. Lee
„But perhaps the most interesting and surprising thing about QCD at high density is that, by thinking about it, one discoversa fruitful new perspective on the traditional problem of confinement and chiral-symmetry breaking”.F. WilczekF. Wilczek
Mapping the QCD phase diagram with heavy-ion collisions
Critical endpoint:Z. Fodor, S. Katz, hep-lat/0402006S. Ejiri et al., hep-lat/0312006μB < 400 MeV: crossover
SIS100/300
ε=0.5 GeV/fm3
baryon density: B 4 ( mT/2)3/2 x
[exp((B-m)/T) - exp((-B-m)/T)] baryons - antibaryons
Strongly interacting matter in neutron stars
F. Weber J.Phys. G27 (2001) 465
“Strangeness" of dense matter ?In-medium properties of hadrons ?Compressibility of nuclear matter?
Deconfinement at high baryon densities ?