Status of the CBM experiment V. Friese Gesellschaft für Schwerionenforschung Darmstadt, Germany for the CBM Collaboration

2 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese nuclei hadronic phase The goal of high energy heavy-ion physics: Exploring the QCD phase diagram SPS RHIC dilute hadron gas RHIC, SPS : crossover QGP  hadrons almost immediate freeze-out dense bayonic medium lattice QCD : Fodor / Katz, Nucl. Phys. A 715 (2003) 319 SIS300 : system experiences a stage of dense baryonic matter may come near to the end point: critical phenomena ? SIS300

3 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese 30 AGeV : Exciting physics NA49, J. Phys. G 29 (2003), and preliminary AGS SPS RHIC Au+Au / Pb+Pb p+p Sharp structure in K + /  + exc. fct., constancy of kaon slopes : Signal of 1 st order PT ? That’s where CBM will measure !

4 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese Physics questions and observables Hadron properties in dense matter Chiral symmetry restoration, generation of hadron masses Penetrating probes :   e + e - 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/   e + e - Nuclear equation of state at highest baryon densities Exc. fct. of particle production and collective flow

5 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese Challenges and opportunities   e + e -, J/   e + e -, , 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 W. Cassing et al, Nucl. Phys. A 691(2001) 753

6 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese Conditions and requirements High track multiplicity ( ) Beam intensity 10 9 ions/sec. High interaction rate (10 MHz) Detector tasks: Tracking in high-density environmentSTS + TRD Reconstruction of secondary vertices (resolution  50  m)STS Hadron identification :  / K / p separation (  t  80 ps) TOF Lepton identification :  / e separation (pion suppression )TRD + RICH central 25 AGeV, UrQMD + GEANT Need fast and radiation hard detectors

7 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese The CBM detector Setup in GEANT4

8 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese Feasibility, Simulations D  Kπ(π) GSI Darmstadt, Czech Acad. Sci., Rez Techn. Univ. Prague ,ω,   e + e - Univ. Krakow,JINR-LHE Dubna J/ψ  e + e - INR Moscow Hadron ID Heidelberg Univ,Warsaw Univ. Kiev Univ. NIPNE Bucharest INR Moscow GEANT4: GSI Tracking KIP Univ. Heidelberg Univ. Mannheim JINR-LHE Dubna Design & construction of detectors Silicon Pixel IReS Strasbourg Frankfurt Univ., GSI Darmstadt, RBI Zagreb, Krakow Univ. LBNL Berkeley Silicon Strip SINP Moscow State U. CKBM St. Petersburg KRI St. Petersburg RPC-TOF LIP Coimbra, Univ. S. de Compostela, Univ. Heidelberg, GSI Darmstadt, NIPNE Bucharest INR Moscow FZ Rossendorf IHEP Protvino ITEP Moscow Fast TRD JINR-LHE, Dubna GSI Darmstadt, Univ. Münster INFN Frascati Straw tubes JINR-LPP, Dubna FZ Rossendorf FZ Jülich ECAL ITEP Moscow RICH IHEP Protvino Trigger, DAQ KIP Univ. Heidelberg Univ. Mannheim GSI Darmstadt KFKI Budapest Silesia Univ. Magnet JINR-LHE, Dubna GSI Darmstadt Analysis GSI Darmstadt, Heidelberg Univ, Data Acquis., Analysis R&D working packages

9 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese Feasibility study : open charm Key variable to suppress background: secondary vertex position D 0  K -  + (central 25 AGeV) c  = 124  m, BR = 3.8 % BG suppression 2 x 10 5 Assuming = : S/B  1 SNR = 3 at 2 x 10 6 events detection rate 13,000 / h Similar study for D +  K -  +  + (c  = 315  m, BR = 9 %) First estimate S/B  3 Crucial detector parameters: Material in tracking stations Single hit resolution

10 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese Monolithic Active Pixel Sensors (MAPS) Pitch 20  m Low material budget : Potentially d = 20  m Excellent single hit resolution :  3  m S/N = R&D (IReS / LEPSI Strasbourg) : radiation hardness, readout speed MIMOSA IV Fallback solution : hybrid pixel detectors see talk by P. Riedler

11 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese K /  separation by time of flight Separation power depends on:  flight path  time resolution

12 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese Time of flight : K - identifcation for D 0 Decay + PID efficiency K - from D 0 decay Key issues for detector design :  rate capability  time resolution  scale

13 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese Detector R&D : Resistive Plate Chambers (RPC) Recent developments at LIP Coimbra : Time resolution (  90 ps) essentially unchanged up to 25 kHz/cm 2 Challenge : Counting rate

14 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese FOPI-RPC-R&D 90 cm-14 strips-4 gaps  t < 80 ps Tail < 2% Detector resolution In house developments: 90 cm-14 strips anode 2 RPCs in gas box

15 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese Feasibility study: J/   e + e - with cuts: p t (e +,e - ) > 1 GeV/c,  lab  25 o,  > 10 o without cuts (incl. misident. pions)  e + e -  e + e - DD  e + e - +X  e + e - J/  e + e - sum Study in CDR : S/B  10 after cuts Now available:  conversion in detector material dominating component, but mostly at low p t study ongoing

16 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese Feasibility study :   e + e - Background from  conversion dominates After cut on e + e - vertex : SNR  3 in 1 M events study ongoing, tracking needed

17 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese Tracking in the STS TRACK RECONSTRUCTION XZ (bending) / YZ (non-bending) TRACK RECONSTRUCTION XZ (bending) / YZ (non-bending)

18 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese Tracking in the STS RECONSTRUCTION PROGRAM based on the Cellular Automaton Method (KIP Heidelberg) RECONSTRUCTION PROGRAM based on the Cellular Automaton Method (KIP Heidelberg) RECO STATISTICS 100 events Refprim efficiency : | Refset efficiency : | Allset efficiency : | Extra efficiency : | Clone probability : | 7 4 Ghost probability : 5.18 | 3358 Reco MC tracks/event : 6 48 Timing/ event : 175 ms RECO STATISTICS 100 events Refprim efficiency : | Refset efficiency : | Allset efficiency : | Extra efficiency : | Clone probability : | 7 4 Ghost probability : 5.18 | 3358 Reco MC tracks/event : 6 48 Timing/ event : 175 ms RECONSTRUCTION Fetch ROOT MC data Copy to local arrays and sort Create segments Link segments Create track candidates Select tracks Reconstruction efficiency > 95 %

19 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese Magnet design Superconducting dipole magnet Field  1 T over 1 m Field calculatiop by TOSCA

20 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese DAQ / Trigger Architecture clock Practically unlimited size Max. latency uncritical Avr. latency relevant Detector Front end ADC Buffer memory Event builder and selector Self triggered digitization: Dead time free Each hit transported as Address/Timestap/Value Compensates builder/selector latency Use time correlation of hits to define events. Select and archive. Challenge : reconstruct 1.5 x 10 9 track/sec. data volume in 1 st level trigger  50 Gbytes/sec. see talk by L. Schmitt

21 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese 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 CBM participation in EU programmes

22 2. Workshop „Challenges and Opportunities“, GSI, October 2003 V. Friese 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 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 The CBM R&D Collaboration : 35 institutions