Silicon Tracking System in CBM experiment

1. Physics motivation • Detector concept • STS • Plans Silicon Tracking System in CBM experiment Paweł Staszel Jagiellonian University

3. 8-40 GeV/n

4. CBM (Compressed Baryonic Matter) net-baryon density created in central Au+Au

5. 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, Λc....)‏ and by collective motion (flow) of the created soft medium. (e .g. v2 is sensitive to the quanta interaction just after the medium formation)

6. 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, Λc....)‏ and by collective motion (flow) of the created soft medium. (e .g. v2 is sensitive to the quanta interaction just after the medium formation) large advantage from simultaneous measurement of “ordinary” hadrons and rare probes ⇒ probing medium with known overall characteristics

7. Projects to explore phase diagram at large mB RHIC energy-scan ................................ bulk observables NA61@SPS......................................... bulk observablesMPD@NICA........................................ bulk observables CBM@FAIR........................................ bulk and rare observables

8. Transition Radiation Detectors Ring Imaging Cherenkov Detector Electro- magnetic Calorimeter Silicon Tracking Stations Projectile Spectator Detector (Calorimeter) Vertex Detector Resistive Plate Chambers (TOF) Dipol magnet

9. CBM Detector (->+-)‏ ECAL (12 m)‏ ABSORBER (1,5 m)‏ magnet TOF (10 m)‏ PSD (~15 m)‏ TRDs (4,6,8 m)‏ STS ( 5 – 100 cm)‏ beam

10. CBM Target region Silicon Tracking System, Micro Vertex Detector, Target, Beam pipe, Superconducting Dipole Magnet MVD: 2 detectors stations vacuum vessel STS: 8 detectors stations in thermal enclosure 10

11. 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 radiation hard and fast silicon pixel and strip detectors c = 312 m self triggered FEE high speed DAQ and trigger online track reconstruction!

12. Silicon Tracking Performance [%] 96% <1 % ghost tracks p [GeV/c] [%] 1.3% (tracks pointing to primary vertex) p [GeV/c] A. Bubak, 19:40 on Wednesday reconstruction efficiency central Au+Au 25 AGeV (UrQMD) 700 reconstructed tracks Cellular Automaton and Kalman Filter, 50 ms on Pentium 4 X-Z view momentum resolution momentum resolution Y-X view

13. Hyperons: PID from decay topology in STS  

14. Feasibility studies for dilepton measurements Signal and background yields from physics event generators (HSD, UrQMD) Full event reconstruction based on realistic detector layout and response 200k events 4 1010 events Electron id: RICH and TRD ρ,ω,φ J/ψ π suppression: factor 104 dominant background: e from π0 Dalitz 4 108 events 3.8 1010 events Muon id: segmented hadron absorber + tracking system 125(225) cm iron, 15(18) det. layers 125 cm Fe: 0.25 ident. /event dominant background: μ from π, K decay (0.13/event) ρ, ω, φ J/ψ, ψ'

15. D0 → K π, cτ= 123 μm D→ K ππ, cτ= 317 μm 1010 centr. ev. eff = 4.4% S/B = 6.4 (D0) 2.1 (D0) 109 centr. ev. eff = 2.6% S/B = 2.4 (D-) 1.1 (D+) _ Open charm measurement • STS: 8 stations double-sided Silicon micro-strip sensors (8  0.4% X0) • MVD: 2 stations MAPS pixel sensors (0.3% X0, 0.5% X0) at z = 5cm and 10cm • no K and π identification, proton rejection via TOF 10 weeks data taking reduced interaction rate 105/s: and

16. Performance summary Maximum beam intensity: 109 ions/s 10 weeks of Au-beam at 25 AGeV beam energy • Minimum bias collisions can be recorded with 25kHz → unlimited statistics for bulk observables (K, L) → 106 r, w, f mesons, 108X, 106W (spectra, flow, correlations, fluctuations) • Open charm trigger will allow for 100kHz → 104 open charm hadrons • Charmonium trigger with max. beam intensity: 10MHz → 106 J/Y • (charm production, spectra, flow measurement)

17. STS Layout

18. Silicon Tracking System ~1m

19. Mechanics & Cooling

20. Demonstrator modules Assembled at SE SRTIIE, Kharkov, Ukraine Single-detector module (CBM03-ISTC) more then 4 000 bonds more then 12 000 bonds Triple-detector module (CBM03-ISTC)

21. Plans

22. STS project time line • R&D: 2011 – 8/2013 • Production: 2013 – 6/2017 • Pre-production: 2013 – 3/2015 • Pre-production at GSI • Pre-production at AGH • Pre-production at PIT - Tübingen • Pre-production at JINR - Dubna • Pre-production at JU • Production Readiness Report: 1.8.2013 • Series production: 2015 – 6/2017

23. Plans In order to integrate partial STS R&D, and to prepare for production phase PIT, AGA and JU prepared application (submitted to NupNET - failed) The application addresses: -> modules assembly, -> series production quality assurance, -> mass testing and -> the development of radiation hard front-end ASICs. The goal is to make a first prototype STS module and make a full characterization using dedicated FEE and R/O.

25. BACKUP SLIDES

28. 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)

29. CBM Collaboration China: Tsinghua Univ., Beijing CCNU Wuhan USTC Hefei Croatia: University of Split RBI, Zagreb Univ. Mannheim Univ. Münster FZ Rossendorf GSI Darmstadt Univ. Kashmir, Srinagar Banaras Hindu Univ., Varanasi Korea: Korea Univ. Seoul Pusan National Univ. Russia: IHEP Protvino INR Troitzk ITEP Moscow KRI, St. Petersburg Hungaria: KFKI Budapest Eötvös Univ. Budapest Norway: Univ. Bergen Kurchatov Inst. Moscow LHE, JINR Dubna LPP, JINR Dubna India: Aligarh Muslim Univ., Aligarh IOP Bhubaneswar Panjab Univ., Chandigarh Gauhati Univ., Guwahati Univ. Rajasthan, Jaipur Univ. Jammu, Jammu IIT Kharagpur SAHA Kolkata Univ Calcutta, Kolkata VECC Kolkata Cyprus: Nikosia Univ. Poland: Krakow Univ. Warsaw Univ. Silesia Univ. Katowice Kraków AGH (Inst. Nucl. Phys. Krakow)‏ LIT, JINR Dubna MEPHI Moscow Obninsk State Univ. PNPI Gatchina SINP, Moscow State Univ. St. Petersburg Polytec. U. Czech Republic: CAS, Rez Techn. Univ. Prague France: IPHC Strasbourg Portugal: LIP Coimbra Romania: NIPNE Bucharest Bucharest University Ukraine: INR, Kiev Shevchenko Univ. , Kiev Germany: Univ. Heidelberg, Phys. Inst. Univ. HD, Kirchhoff Inst. Univ. Frankfurt 55 institutions, > 400 members Dubna, Oct 2008

30. 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

31. Mapping the QCD phase diagram with heavy-ion collisions SIS300 net baryon density: B 4 ( mT/2h2c2)3/2 x [exp((B-m)/T) - exp((-B-m)/T)] baryons - antibaryons Lattice QCD calculations: Fedor & Katz, Ejiri et al.