strangeness and charm in the cbm experiment
DESCRIPTION
Strangeness and Charm in the CBM Experiment. V. Friese Gesellschaft f ür Schwerionenforschung Darmstadt, Germany [email protected]. for the CBM collaboration. The QCD Phase Diagram and SIS 300. Beam energy 10 – 45 AGeV: highest baryon densities first order phase transition - PowerPoint PPT PresentationTRANSCRIPT
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Volker Friese SQM 2006, Los Angeles, March 2006 1
Strangeness and Charm in the CBM Experiment
V. FrieseGesellschaft für Schwerionenforschung
Darmstadt, [email protected]
for the CBM collaboration
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Volker Friese SQM 2006, Los Angeles, March 2006 2
The QCD Phase Diagram and SIS 300
Beam energy 10 – 45 AGeV:
highest baryon densities
first order phase transition
critical point ?
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Baryon & Energy Densities @ SIS 300
C. Fuchs, E. Bratkovskaya, W. Cassing
Large energy and baryon densities accessible
ε > εcrit for large part of system evolution
Similar results from QGSM
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Trajectories in the Phase Diagram
3-Fluid Hydro calculation with hadron gas EOS (Ivanov, Russkikh, Toneev, nucl-th/0503088)
Early phase not equilibrated
Predicts reaching the phase boundary for 10 AGeV
30 AGeV trajectory near critical point
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Trajectories in the Phase Diagram (2)
UrQMD transport (hadrons, strings, reonances)Stöcker, nucl-th/0506013
Qualitativ agreement with 3-Fluid-Hydro
Phase border in reach, maybe critical point also
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Something's going on at low energies
Gazdzicki, Gorenstein, Act. Phys. Polon. B 30 (1999) 2705
Anomaly in relative strangeness
Plateau in pt slopes
K/π fluctuations exceed UrQMD
v2 underpredicted by UrQMD from 30 AGeV on
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CBM: Physics Topics & Observables
Equation-of-state at high B
collective flow of hadrons, particle production at threshold energies (open charm) Deconfined phase at high B Strangeness production K, , , , Charmonium suppression ? Charmonium (J/ψ, ψ'), open charm (D0, D)
Chiral symmetry restoration at high B
In-medium modifications of hadrons , , e+e- , open charm, ..... 1. order phase transition & its critical endpoint Event-by-event fluctuations (K/π, pT, ...)
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CBM: Experimental Programme
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
Detector requirementsLarge geometrical acceptance (azimuthal symmetry !)good hadron and electron identificationexcellent vertex resolutionhigh rate capability of detectors, FEE and DAQ
Large integrated luminosity:High beam intensity and duty cycle,Available for several month per year
High rates, rare probes
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The FAIR Facility
existing GSI facilitiesSIS 100/300
CBM
Primary beams: •1012/s; 1.5-2 GeV/u; 238U28+
• 4x1013/s 90 GeV protons• 1010/s 238U 35 GeV/u ( Ni 45 GeV/u)
Secondary beams: •rare isotopes 1.5 - 2 GeV/u; factor 10 000 increased intensity • antiprotons 3(0) - 30 GeV
Storage and cooler rings• e – A Collider• rare isotopes
• 1011 stored and cooled antiprotons
0.8 - 14.5 GeV• Relativistic heavy-ion physics• Hadron physics with antiproton beam• Plasma physics with pulsed beams• Nuclear structure with radioactive ion beams•Atomic physics
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Experimental Challenges
reconstruction of ≈1000 charges particles per event, kinematically focussed
extremely rare probes: D, J/ψ (10-5 – 10 -4)
high rates: up to 107/s (beam 109/s)
displaced vertex determination accuracy ≈ 50 μm
hadron & lepton ID
25 AGeV Au+Au, UrQMD+GEANT4
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The CBM Detector
Radiation hard Silicon Tracking System in dipole field
Electron ID in RICH+TRD+ECAL
Hadron ID in TOF (RPC)
γ, μ, π in ECAL
High-speed DAQ and trigger system
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Detector R&D
Charge [ADC]
after 1 MRad
Radiation hardness of pixel sensors
RICH optical layoutRadiator gas, mirror material, photodetectors
TRD rate capability
RPC rate capability and large area coverage
R&D ongoing and promising
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Simulations – Level of Reality
Full track reconstruction (STS)Pattern recognition in RICH
Primary & secondary vertex reconstructionGlobal tracking under work
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Acceptance for TOF-identified Hadrons
Bulk of hadrons can be identified by STS + TOF
Improvement for kaons by RICH (?)
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Performance for Hyperons
Λ Ξ- Ω-
Hyperons reconstructable almost background-free
15.8% 6.7% 7.7%
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Performance for D mesons
Au+Au @ 25 AGeV, 1012 events min bias, full track and vertex reconstructionD multiplicity taken from HSD, background UrQMDno PID of secondaries
D0
D+
80,000 D+ in 1012 min bias events1 day of full luminosity running
100 days with today´s MAPS performance
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Performance for J/ψ
15 AGeV Au+Au
25 AGeVAu+Au
35 AGeVAu+Au
via e+e-
assumed pion suppression 10-4
studies ongoing
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Performance for Flavour Fluctuations
4 acceptance identified
particles
K/ 3.2 0.3 2.6 0.6
p/ -5.3 0.07 -5.9 0.1
sensitive to fluctuations within 1 %
datamixed eventsUrQMD Au+Au, 25 AGeV
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The Muon OptionC/Fe absorbers + detector layers
Promising for J/ψ
Low efficiency for soft muons
Low efficiency for invariant masses below 0.5 GeV
Very challenging muon detector (high densities)
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The CBM Physics Group
established June 2005
1st CBM Physics Workshop December 2005, GSI
2nd Physics Workshop: June 2006, ECT Trento
CBM Physics Book in ≈ 1 year
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CBM: Status
Nov. 2001: FAIR Conceptual Design Report
Jul. 2002: FAIR Recommendation by german Wissenschaftsrat
Feb. 2003: FAIR approved by BMBF
Jan. 2004: CBM Letter of Intent approved "core experiment of FAIR"
Jan. 2005: CBM Technical Status Report
June 2005: CBM Physics Group established
March 2006: Fed. Gouvernment: FAIR in budgetary plan up to 2014
2007: CBM Technical Proposal
http://www.gsi.de/fair/experiments/CBM
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The CBM collaboration
40 institutions, ≈ 350 Members
Croatia: RBI, Zagreb
China:Wuhan Univ.Hefei Univ.
Cyprus: Nikosia Univ. Czech Republic:CAS, RezTechn. Univ. Prague
France: IReS Strasbourg
Hungaria:KFKI BudapestEötvös Univ. Budapest
India:VECC Kolkata
Romania: NIPNE Bucharest
Russia:IHEP ProtvinoINR TroitzkITEP MoscowKRI, St. PetersburgKurchatov Inst., MoscowLHE, JINR DubnaLPP, JINR DubnaLIT, JINR DubnaMEPHI MoscowObninsk State Univ.PNPI GatchinaSINP, Moscow State Univ. St. Petersburg Polytec. U.
Ukraine: Shevshenko Univ. , Kiev
Korea:Korea Univ. SeoulPusan National Univ.
Norway:Univ. Bergen
Germany: Univ. Heidelberg, Phys. Inst.Univ. HD, Kirchhoff Inst. Univ. FrankfurtUniv. KaiserslauternUniv. Mannheim Univ. MünsterFZ RossendorfGSI Darmstadt
Poland:Krakow Univ.Warsaw Univ.Silesia Univ. Katowice Portugal: LIP Coimbra