future physics with cbm paweł staszel jagiellonian university physics motivation detector concept...
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Future Physics with CBM
Paweł StaszelJagiellonian University
Physics motivation Detector concept Feasibility study Status
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 2
CBM (Compressed Baryonic Matter)
net-baryon density created in central Au+Au
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 3
Diagram fazowy QCD
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 4
QCD Phase Diagram scan with A+Acollisions
Y.B Ivanov et al., Phys. Rev. C 73, 044904 (2006)
3 component hydrodynamics + hadron gas EOS:
Critical Point reached at trajectory for ~30 AGeV (s
NN=7.74)
Phase Boundary reached already at ~10 AGeV (s
NN=4.72)
How to explore interesting regions of the QCD Phase Diagram
Lattice QCD calculations:Fedor & Katz,Ejiri et al.
Freeze-out phase can be studied by measurement of „soft” hadrons production (bulk observables)
Information about earlier phases is carried by rare probes:
• High pT particles
• Particles decaying into leptons• Particles build up of heavy quarks (J/ψ, D, Λ
c ....)
and by collective motion (flow) of the created soft medium. (e .g. v
2 is
sensitive to the quanta interaction just after the medium formation)
large advantage from simultaneous flow measurement of “ordinary” hadrons and rare probes
Future projects to explore phase diagram at large
RHIC energy-scan ................................ bulk observablesNA61@SPS ......................................... bulk observables
MPD@NICA ........................................ bulk observables
CBM@FAIR ........................................ bulk and rare observables
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 7
Experymental arguments for Phase Transition at low SPS energy
NA49 (QM 2004)
None monotonic behaviour of K+/+ ratio
Effective temperature shows plateau in the range of SPS energy
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 8
Kaon spectra versus hadronic models
UrQMD and HSD models can describe p+p and light Ion data (C+C).
Description of kaon spectra in central Au+Au and Pb+Pb requires contribution from strong parton-parton interactions in the early phase
E. Bratkovskaya et al. PRL 92, 032302 (2004)
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 9
Hadrons in dense medium (->+-)
NA60, Nucl. Phys. A 774 (2006) 67
broadening of spectral function (Rapp-Wambach)
contradiction with mass drop scenario (Brown-Rho scaling)
excess by factor of 4 over the “cocktail” with 25% systematic uncertainty !
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 10
Updates on +- results
Good pair excess description for M > 1 GeV assuming thermal QGP (q+qbar → contribution
J. Rappert et al. PLB 100, 162301 (2008)
For M up to ~0.9 MeV Teff
scales with
M → radial flow on hadronic levelFor M > 1 GeV partonic contribution
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 11
Open charm in dense medium
A. Mishra et al., Phys. Rev. C 69, 015202 (2004)
Reduction in the effective mass of D-meson can open D-Dbar decay channel for charmonium states → possible scenario for the J/Ψ suppression, CBM=> simultaneous measurement of J/Ψ and D-mesons
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 12
J/Ψ suppression
Anomalous J/ψ suppresion (AS) on SPS, L – effective path in medium
NA50, QM 2005
NA60 evidenced same effect in In+In
Better scaling is obtained in Npart
; onset already at Npart
~90,
At lower energies (larger μB) one can expect onset of AS for more central collisions
→ dependency on energy density and μB Important measurement of open charm to verify other scenarios
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 13
Event-by-event fluctuations
[NA49 collaboration, arXiv:0810.5580v2 [nucl-ex]]
• observation might become enormously difficult
• correlation length of sigma field, may become rather small for a finite lifetime of the fireball
• large acceptance needed!
2
2
pt
pt
pt zN
Z=Φ
N
=ittipt
ttpt
pp=Z
pp=z
1
[Stephanov, Rajagopal, Shuryak, PRD60, 114028 (1999)]
fluctuations, correlations with large acceptance and particle identification
K. Grebieszków on Thursday
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 14
CBM: Physics topics and Observables
Onset of chiral symmetry restoration at high B and tracing medium properties in time • in-medium modifications of hadrons (,, e+e-(μ+μ-), D)
Deconfinement phase transition at high B
• excitation function and flow of strangeness (K, )• excitation function and flow of charm (J/ψ, ψ', D0, D,
c)
charmonium suppression, sequential for J/ψ and ψ' ? corelated with open charm ?
The equation-of-state at high B
• collective flow of hadrons• particle production at threshold energies (open charm)
QCD critical endpoint• excitation function of event-by-event fluctuations (K/π,...)
predictions? clear signatures?→ be prepared to measure "everything": bulk particles and rare probes → probing medium with known overall characteristics→ systematic studies! (pp, pA, AA, energy)
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 15
CBM Detector (->e+e-)
TRDs(4,6,8 m)
STS ( 5 – 100 cm)
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 16
CBM Detector (->+-)
beam
ABSORBER(1,5 m)
TRDs(4,6,8 m)
TOF(10 m)
ECAL(12 m)
STS ( 5 – 100 cm)
magnet
PSD(~15 m)
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 17
Silicon Tracking System – heart of CBM
Challenge: high track density: 600 charged particles in 25o @10MHz
Tasks:• track reconstruction: 0.1 GeV/c < p 10-12 GeV/c p/p ~ 1% (p=1 GeV/c)• primary and secondary vertex reconstruction (resolution 50 m)
V0 track pattern recognition
c = 312 m
radiation hard and fast silicon pixel and strip detectors
self triggered FEE
high speed DAQ and trigger
online track reconstruction!
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 18
Silicon Tracking Performance
momentum resolution1.3%
(tracks pointing to primary vertex)
[%
]
p [GeV/c]
central Au+Au 25 AGeV (UrQMD)
700 reconstructed tracks
X-Z view
Y-X view
<1 % ghost tracks
96%
[%
]
p [GeV/c]
reconstruction efficiency
momentum resolution
Cellular Automaton and Kalman Filter,
50 ms on Pentium 4
A. Bubak, 19:40 on Wednesday
Hyperons: PID from decay topology in STS
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 20
Simulation: bulk particles and hyperons
0
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y0 0.5 1 1.5 2 2.5 3 3.5 4
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$V/c
]T
p
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$V/c
]T
p
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$V/c
]T
p
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2
incl. TOF
10 35AGeV
Λ Ξ Ω
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 21
ρ,ω,φ
ρ, ω, φ J/ψ, ψ'
Signal and background yields from physics event generators (HSD, UrQMD) Full event reconstruction based on realistic detector layout and response
Feasibility studies for dilepton measurements
Electron id:RICH and TRD
Muon id:segmented hadron absorber+ tracking system
125(225) cm iron,15(18) det. layers
π suppression:
factor 104
dominant background: e from π0 Dalitz
125 cm Fe: 0.25 ident. /event
dominant background: μ from π, K decay (0.13/event)
J/ψ
200k events 4 1010 events
4 108 events 3.8 1010 events
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 22
STS: 8 stations double-sided Silicon micro-strip sensors (8 0.4% X0)
MVD: 2 stations MAPS pixel sensors (0.3% X0, 0.5% X
0) at z = 5cm and 10cm
no K and π identification, proton rejection via TOF
~ 12k D+ + 26k D- 10 weeks data taking reduced interaction
rate 105/s:
Open charm measurement
D → K π π, cτ= 317 μm109 centr. ev.
eff = 2.6%
S/B = 2.4 (D-) 1.1 (D+)
D0 → K π, cτ= 123 μm1010 centr. ev.
eff = 4.4%
S/B = 6.4 (D0) 2.1 (D0)
_
and~ 7k D0 + 20k D0
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 23
Performance summary
Maximum beam intensity: 109 ions/s10 weeks of Au-beam at 25 AGeV beam energy
• Minimum bias collisions can be recorded with 25kHz→ unlimited statistics for bulk observables (K, )→ 106 mesons, 108 , 106 (spectra, flow, correlations, fluctuations)
• Open charm trigger will allow for 100kHz → 104 open charm hadrons• Charmonium trigger with max. beam intensity: 10MHz→ 106 J/• (charm production, spectra, flow measurement)
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 24
Status
CBM Collaboration undergoes (phase) transition
simulation → prototyping
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 25
Double and triple GEM detectors2 Double-sided silicon microstrip detectors Radiation tolerance studies for readout electronics Full readout and analysis
chain:
Front-end board with self-triggering n-XYTER chip Readout controller
Data Acquisition System
online
offline
Go4
AnalysisDetector
signals
Successful test of CBM prototype detector systems with free-streaming read-out electronics using proton beams at GSI, September 28-30, 2008
GSI and AGH Krakow VECC Kolkata KIP Heidelberg
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 26
CBM hardware R&D
RICH mirror
n-XYTER FEB
Silicon microstrip detector
MVD: Cryogenic operation in vacuum RPC R&D
Forward Calorimeter
GEM
dipole magnet
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 27
90 pages, available at www.gsi.de/fair/experiments/CBM
CBM Progress Report 2008
Content:• Micro Vertex Detector
• Silicon Tracking System
• Ring Imaging Cherenkov Detector
• Muon System
• Transition Radiation Detectors
• Resistive Plate Chambers
• Calorimeters
• Magnet
• FEE and DAQ
• Physics Performance
• Software and Algorithms
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 28
CBM CollaborationChina:Tsinghua Univ., BeijingCCNU WuhanUSTC Hefei
Croatia:
University of SplitRBI, Zagreb
Portugal: LIP Coimbra
Romania: NIPNE BucharestBucharest University
Poland:Krakow Univ.Warsaw Univ.Silesia Univ. KatowiceKraków AGH(Inst. Nucl. Phys. Krakow)
LIT, JINR DubnaMEPHI MoscowObninsk State Univ.PNPI GatchinaSINP, Moscow State Univ. St. Petersburg Polytec. U.
Ukraine: INR, KievShevchenko Univ. , Kiev
Univ. MannheimUniv. MünsterFZ RossendorfGSI Darmstadt
Czech Republic:CAS, RezTechn. Univ. Prague
France: IPHC StrasbourgGermany: Univ. Heidelberg, Phys. Inst.Univ. HD, Kirchhoff Inst. Univ. Frankfurt
Hungaria:KFKI BudapestEötvös Univ. BudapestIndia:Aligarh Muslim Univ., AligarhIOP BhubaneswarPanjab Univ., ChandigarhGauhati Univ., Guwahati Univ. Rajasthan, JaipurUniv. Jammu, JammuIIT KharagpurSAHA KolkataUniv Calcutta, KolkataVECC Kolkata
Univ. Kashmir, SrinagarBanaras Hindu Univ., Varanasi
Korea:Korea Univ. SeoulPusan National Univ.Norway:Univ. Bergen
Kurchatov Inst. MoscowLHE, JINR DubnaLPP, JINR DubnaCyprus:
Nikosia Univ.
55 institutions, > 400 members
Dubna, Oct 2008
Russia:IHEP ProtvinoINR TroitzkITEP MoscowKRI, St. Petersburg
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 29
Hadrons in dense medium (->e+e-)
Top SPS: excess of e+e- pairs around 0.5 GeV (by factor of ~2.8)40AGeV: the excess rised up to ~4 → strong dependency on
B
Rapp-Wambach – in-medium modification
Rapp: “dropping mass” according to Brown-Rho scaling scenario
Thermal model
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 30
Elliptic flow at RHIC (√SNN
= 200 GeV)
gPHENIX, PRL.98:162301,2007
baryons mezonsn 3 2
KET = m
T - m
• all particles flow (even these with charm!) → strong interactions
• scaling if taking the underlying number of quarks into account!→quark combine to hadrons at a later stage (hadronization via coalescence)
data can only be explained assuming a large, early built up pressure in a nearly ideal liquid (low viscosity!)
→ sQGP
Elliptic flow at SPS
data at top SPS support hypothesis of early development of collectivity• influence of hadronic rescattering phase, resonance decay? • lack of complete thermalization, viscosity effect?• larger pt-range needed
Pb+Pb collisions, √sNN
= 17.3 GeV
[NA49, G. Stefanek, PoS CPOD2006:030,2006]
Paweł Staszel Konwersatorium PTF oddział katowicki, Katowice 25.02.2009 33
In parallel, in time steps of 10-100s in SIS100/300 proton/heavy ion beams are accelerated to high energy: 90GeV – protons, 45GeV – heavy ions
High energy proton and heavy ion beam are gradually extracted for HADES+ and CBM experiments
Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 34
Mapping the QCD phase diagram with heavy-ion collisions
net baryon density: B 4 ( mT/2h2c2)3/2 x [exp((B-m)/T) - exp((-B-m)/T)] baryons - antibaryons
Lattice QCD calculations:Fedor & Katz,Ejiri et al.
SIS300