Status of the CBM experiment

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Status of the CBM experiment
V. Friese Gesellschaft für Schwerionenforschung Da
rmstadt, Germany v.friese_at_gsi.de
for the CBM Collaboration
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The goal of high energy heavy-ion physics
Exploring the QCD phase diagram
lattice QCD Fodor / Katz, Nucl. Phys. A 715
(2003) 319
dense bayonic medium
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30 AGeV Exciting physics
Sharp structure in K/? exc. fct., constancy of
kaon slopes Signal of 1st order PT ?
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Physics questions and observables
Hadron properties in dense matter Chiral symmetry
restoration, generation of hadron
masses Penetrating probes ? ? ee- with high
precision / statistics Threshold production of
open charm D ? hadrons
Deconfinement, phase transition, critical
phenomena Strangeness production, flow,
fluctuations ?, K , p direct ?, ?, ? via decay
topology J/? ? ee-
Nuclear equation of state at highest baryon
densities Exc. fct. of particle production and
collective flow
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Challenges and opportunities
? ? ee-, J/? ? ee-, ?, D extremely rare
probes !
Highest beam intensities / interaction rates
needed !
Opportunity Systematic measurement of these
probes as function of beam energy and
projectile/target size
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Conditions and requirements
High track multiplicity (700-1000) Beam intensity
109 ions/sec. High interaction rate (10 MHz)
Need fast and radiation hard detectors
Detector tasks Tracking in high-density
environment STS TRD Reconstruction of
secondary vertices (resolution ? 50
?m) STS Hadron identification ? / K / p
separation (?t ? 80 ps) TOF Lepton
identification ? / e separation (pion
suppression 10-4) TRD RICH
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The CBM detector
Setup in GEANT4
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RD working packages
Feasibility, Simulations
Design construction of detectors
Data Acquis., Analysis
GEANT4 GSI
Silicon Pixel IReS Strasbourg Frankfurt
Univ., GSI Darmstadt, RBI Zagreb, Krakow Univ.
LBNL Berkeley
Fast TRD JINR-LHE, Dubna GSI Darmstadt, Univ.
Münster INFN Frascati
Trigger, DAQ KIP Univ. Heidelberg Univ.
Mannheim GSI Darmstadt KFKI Budapest Silesia Univ.
?,?, ? ?ee- Univ. Krakow,JINR-LHE Dubna
D ? Kp(p) GSI Darmstadt, Czech Acad. Sci.,
Rez Techn. Univ. Prague
RPC-TOF LIP Coimbra, Univ. S. de
Compostela, Univ. Heidelberg, GSI
Darmstadt, NIPNE Bucharest INR Moscow FZ
Rossendorf IHEP Protvino ITEP Moscow
Silicon Strip SINP Moscow State U. CKBM St.
Petersburg KRI St. Petersburg
Analysis GSI Darmstadt, Heidelberg Univ,
J/? ? ee- INR Moscow
Hadron ID Heidelberg Univ,Warsaw Univ. Kiev
Univ. NIPNE Bucharest INR Moscow
Straw tubes JINR-LPP, Dubna FZ Rossendorf FZ
Jülich
Magnet JINR-LHE, Dubna GSI Darmstadt
Tracking KIP Univ. Heidelberg Univ.
Mannheim JINR-LHE Dubna
ECAL ITEP Moscow
RICH IHEP Protvino
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Feasibility study open charm
D0 ? K-? (central AuAu _at_ 25 AGeV) c? 124 ?m,
BR 3.8 BG suppression 2 x 105 Assuming ltD0gt
10-3 S/B ? 1 SNR 3 at 2 x 106
events detection rate 13,000 / h
Key variable to suppress background secondary
vertex position
Similar study for D ? K- ? ? (c? 315 ?m, BR
9 ) First estimate S/B ? 3
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Monolithic Active Pixel Sensors (MAPS)
Pitch 20 ?m Low material budget Potentially d
20 ?m Excellent single hit resolution ? 3 ?m
S/N 20 - 40
RD (IReS / LEPSI Strasbourg) radiation
hardness, readout speed
Fallback solution hybrid pixel detectors see
talk by P. Riedler
MIMOSA IV
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K / ? separation by time of flight

• Separation power depends on
• flight path
• time resolution

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Time of flight K- identifcation for D0

• Key issues for detector design
• rate capability
• time resolution
• scale

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Detector RD Resistive Plate Chambers (RPC)
Challenge Counting rate
Recent developments at LIP Coimbra Time
resolution (? 90 ps) essentially unchanged up to
25 kHz/cm2
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FOPI-RPC-RD
90 cm-14 strips anode
In house developments
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Feasibility study J/? ? ee-
Study in CDR S/B ? 10 after cuts Now
available ? conversion in detector
material dominating component, but mostly at low
pt study ongoing
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Feasibility study ? ? e e-
Background from ? conversion dominates After cut
on ee- vertex SNR ? 3 in 1 M events study
ongoing, tracking needed
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Tracking in the STS
TRACK RECONSTRUCTION XZ (bending) / YZ
(non-bending)
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Tracking in the STS
RECO STATISTICS 100 events Refprim efficiency
98.36 46562 Refset efficiency
94.85 49250 Allset efficiency 90.09
64860 Extra efficiency 77.79
15610 Clone probability 0.11
74 Ghost probability 5.18 3358 Reco
MC tracks/event 648 Timing/event
175 ms
RECONSTRUCTION PROGRAM based on the Cellular
Automaton Method (KIP Heidelberg)

• RECONSTRUCTION
• Fetch ROOT MC data
• Copy to local arrays and sort
• Create segments
• Link segments
• Create track candidates
• Select tracks

Reconstruction efficiency gt 95
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Magnet design
Superconducting dipole magnet Field ? 1 T over 1 m
Field calculatiop by TOSCA
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DAQ / Trigger Architecture
clock
Practically unlimited size
Max. latency uncritical Avr. latency relevant
Challenge reconstruct 1.5 x 109
track/sec. data volume in 1st level trigger ? 50
Gbytes/sec.
see talk by L. Schmitt
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CBM participation in EU programmes

• EU FP6 HP
• Joint Research Projects (approved)
• Fast gaseous detectors
• Advanced TOF Systems
• Future DAQ and trigger systems
• Network activities (approved)
• CBMnet

• INTAS
• Submitted proposals to the
• INTAS-GSI joint call
• Silicon Strip Detectors
• Electromagnetic calorimeter
• Transition Radiation detectors
• Straw tube tracker
• Resistive Plate Chambers

Proposals to EU FP6 (Design and Construction of
new facilities) in preparation Call end of 2003
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The CBM RD Collaboration 35 institutions
Russia CKBM, St. Petersburg IHEP Protvino INR
Troitzk ITEP Moscow KRI, St. Petersburg Kurchatov
Inst., Moscow LHE, JINR Dubna LPP, JINR
Dubna SINP, Moscow State Univ. Spain Santiago
de Compostela Univ.   Ukraine Shevshenko
Univ. , Kiev USA LBNL Berkeley
Hungaria KFKI Budapest Eötvös Univ.
Budapest Italy INFN Catania INFN Frascati
Korea Korea Univ. Seoul Pusan
Univ. Poland Krakow Univ. Warsaw Univ. Silesia
Univ. Katowice   Portugal LIP Coimbra Romania
NIPNE Bucharest
Croatia RBI, Zagreb Cyprus Nikosia Univ.
  Czech Republic Czech Acad. Science,
Rez Techn. Univ. Prague   France IReS
Strasbourg Germany Univ. Heidelberg, Phys.
Inst. Univ. HD, Kirchhoff Inst. Univ.
Frankfurt Univ. Mannheim Univ. Münster FZ
Rossendorf FZ Jülich GSI Darmstadt