Fast reconstruction of multi strange particles in the CBM experiment

Transcription

1 Fast reconstruction of multi strange particles in the CBM experiment Oct.1 HYP2012 Barcelona Vassiliev Iouri, CBM Collaboration GSI SIS RICH TRD TOF ECAL CBM STS PSD MUCH 1

2 Physics case: Exploring the QCD phase diagram LHC RHIC SPS-CERN CBM Deconfinement phase transition at high ρ B excitation function and flow of strangeness (K, Λ, Σ, Ξ, Ω...Η 0, 3 Λ Η ) excitation function and flow of charm (J/ ψ, ψ', D 0, D s, D ±, Λ c ) charmonium suppression, for J/ψ and ψ' Onset of chiral symmetry restoration at high ρ B in-medium modifications of hadrons (ρ,ω,φ e + e - (µ + µ - ), D?, Σ *?) QCD critical endpoint excitation function of event-byevent fluctuations (K/π,...) The equation-of-state at high ρ B collective flow of hadrons particle production at threshold energies (open charm) Projects to explore the QCD phase diagram at large µ B : RHIC energy-scan, NA61@SPS, MPD@NICA bulk observables 2 CBM@FAIR/SIS-300 bulk and rare observables, high statistic!

3 Experiments on superdense nuclear matter Why CBM? Experiment BNL CERN Dubna Darmstadt Energy range (Au/Pb beams) Reaction rates Hz s NN = GeV (limitation by luminosity) E kin = A GeV s NN = GeV 80 (limitation by detector) s NN = GeV ~1000 (design luminosity of cm -2 s -1 for heavy ions) E kin = A GeV s NN = GeV (limitation by detector) 3

4 700 π 160 p 53 K 32 Λ 27 K S 0 ~1 Ξ Ω - UrQMD event, central 25AGeV Ø up to 10 7 Au+Au reactions/sec (J/ψ) Ø determination of (displaced) vertices with high resolution ( 50 µm) Ø identification of leptons and hadrons Ø fast and radiation hard detectors Ø self-triggered readout electronics Ø high speed data acquisition and online event selection 4

5 The core detectors: Silicon Tracking System 8 low-mass tracking stations 4 m2 of silicon microstrip detectors σ =32 µm layout optimized for efficient track reconstruction and high momentum resolution. 2.4 GeV protons detailed GEANT models with active and passive materials 5

6 central 25AGeV reconstruction simulation SIS π 160 p 53 K 32 Λ 27 K S 0 ~1 Ξ Ω - 10MHz SIMDized tracking + KFParticle central: 62 (TF) (PF) ms/core mbias : 8 (TF) (PF) ms/cor up to 80 cores/cpu 600 reconstructed tracks Ref. prim. eff = 96% All set eff = 86% dp/p = 1.2% 6

7 KF Par'cle Finder for the CBM Experiment Tracks: e ±, µ ±, π ±, K ±, p ± secondary and primary Open-charm: D 0 π + K - D 0 π + π + π - K - D 0 π - K + D 0 π - π - π + K + D + π + π + K - D - π - π - K + D s + π + K + K - D s - π - K + K - Λ c π + K - p Open-charm resonances: D *0 D + π - D *0 D - π + D *+ D 0 π + D *- D 0 π - Multi-strange hyperons: Ξ - Λ π - Ξ + Λ π + Ω - Λ K - Ω + Λ K + Multi-strange resonances: Ξ *0 Ξ - π + Ξ *0 Ξ + π - Ω *- Ξ - π + K - Ω *+ Ξ + π - K + Strange particles: K 0 s π+ π - Λ p π - Λ π + p - Strange and multistrange resonances: Σ *+ Λ π + Σ *+ Λ π - Σ *- Λ π - Σ *- Λ π + K *- K 0 s π- K *+ K 0 s π+ Ξ *- Λ K - Ξ *+ Λ K + Gamma γ e - e + Strange resonances K *0 K + π - K *0 π + K - Λ * p K - Λ * p - K + Light vector mesons: ρ e - e + ρ µ - µ + ω e - e + ω µ - µ + φ e - e + φ µ - µ + φ K - K + Charmonium: J/Ψ e - e + J/Ψ µ - µ + 7/14

8 Bulk observables: K 0 s and Λ 80k central UrQMD events K 0 S Λ p bar id (TOF) K 0 s 8 8

9 Au+Au, strangeness: Ξ - and Ω - CBM, STAR trigger!? Secondary Λ from Ξ -, Ω - ± 6σ window KFParticle 80k central events, 2.5 hours 724 eff = 0.9% Direct search 1187 Eff=0.55% S/B=0.1 PLUTO generator 9 9

10 SIS-100 pc 30GeV bulk observables: K 0 s and Λ 0.8M events 10 10

11 SIS-100 C+C 10AGeV 6M events 52 Ξ - p_id direct search no Ξ generator 11

12 C+C 25AGeV 12 I.Vassiliev, CBM 12

13 10 MHz IR, high statistic pau 30 GeV K S 0 Λ Σ + Σ - Ξ - decay channel π - π + p π - π + p π - π - p π - π - p π - M HSD ?? BR(%) ~100 total eff. (%) ?? 1.6 S/B 2σ >10 Yield/central int E E E-4 13

14 Up to 10 MHz IR, high statistic Au+Au 8 AGeV K S 0 Λ Ξ - Ω - decay channel π - π + p π - π - p π - K - p π - M HSD BR(%) ~ total eff. (%) S/B 2σ Yield/central int E-5 Au+Au 25 AGeV K S 0 Λ Ξ - Ω - decay channel π - π + p π - π - p π - K - p π - M HSD BR(%) ~ total eff. (%) S/B 2σ Yield/central int E-5 14

15 A.Zinchenko Production of single and double hypernuclei 3 H Λ and 4 H Λ production in Au+Au at 10 AGeV 200k events 200k events How far can we extend the third (strange) dimension of the nuclear chart? 10/9/12 18M events 15

16 s d u s u s? Λ Λ Strange and Hyper matter in the Lab Does strange matter exist in the form of heavy multi-strange objects? J. Steinheimer, K. Gudima, A. Botvina, Mishustin, M. Bleicher, H. Stöcker arxiv: v2 [nucl-th] 11-Jul-2012 CBM detector is an excellent device to measure not only bulk observables, but 10/9/12 16 strangeness and rare (charm) probes with high statistic.

17 CBM timeline R&D detectors & read-out systems construction detectors & read-out systems installation, commissioning first data taking 17

18 he CBM Collaboration: 55 institutions, 450 members Croatia: RBI, Zagreb Split Univ. China: CCNU Wuhan Tsinghua Univ. USTC Hefei Czech Republic: CAS, Rez Techn. Univ.Prague France: IPHC Strasbourg Hungaria: KFKI Budapest Budapest Univ. Norway: Univ. Bergen Germany: Frankfurt Univ. IKF Frankfurt Univ. FIAS GSI Darmstadt Giessen Univ. Heidelberg Univ. P.I. Heidelberg Univ. KIP Heidelberg Univ. ZITI HZ Dresden-Rossendorf Münster Univ. Tübingen Univ. Wuppertal Univ. Korea: Korea Univ. Seoul Pusan Nat. Univ. Romania: NIPNE Bucharest Univ. Bucharest India: Aligarh Muslim Univ. Panjab Univ. Rajasthan Univ. Univ. of Jammu Univ. of Kashmir Univ. of Calcutta B.H. Univ. Varanasi VECC Kolkata SAHA Kolkata IOP Bhubaneswar IIT Kharagpur Gauhati Univ. Poland: AGH Krakow Jag. Univ. Krakow Silesia Univ. Katowice Warsaw Univ. Russia: IHEP Protvino INR Troitzk ITEP Moscow KRI, St. Petersburg Kurchatov Inst., Moscow LHEP, JINR Dubna LIT, JINR Dubna MEPHI Moscow Obninsk State Univ. PNPI Gatchina SINP MSU, Moscow St. Petersburg P. Univ. Ukraine: T. Shevchenko Univ. Kiev Kiev Inst. Nucl. Research 28/02/12 I.Vassiliev, CBM 18 18

19 Backup slides 19

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21 χ 2 fit χ2 given by a track fit χ 2 prim χ2 distance to a primary vertex (PV) χ 2 geo χ2 given by a particle fit χ 2 topo χ2 of a particle fitted to PV KFPar;cle Finder (50 par;cles so far ) Tracks Selected tracks χ 2 fit criterion χ 2 prim criterion Secondary tracks Primary tracks e + e - µ + µ - D 0, D + D s, Λ c candidates D +* K 0 s, Λ and Λ candidates χ 2 geo criterion Selected K 0 s, Λ and Λ Store Selected K 0 s, Λ and Λ check mass χ 2 topo z vertex criteria Secondary Λ and Λ Primary K 0 s, Λ and Λ J/ψ, Ψ e + e - µ + µ - ρ,ω,φ Ξ -, Ξ +, Ω - and Ω + candidates Selected Ξ -, Ξ +, Ω - and Ω + χ 2 geo, χ2 topo, z vertex criteria H-dibaryon candidates Selected H Store χ 2 geo, χ2 topo, z vertex criteria Σ *+, Σ *+, Σ *- and Σ *-, K *0, K *0, K *- and K *+ candidates χ 2 geo criterion Selected Σ *+, Σ *+, Σ *- and Σ *-, K *0, K *0, K *- and K *+ 21

22 Highest net- baryon densi'es at FAIR [J. Randrup, J. Cleymans PRC74, (2006)] beam energy max. ρ/ρ 0 max ε [GeV/fm 3 ] time span ~FWHM 5 AGeV ~ 8 fm/c 40 AGeV 12 > 10 ~ 3.5 fm/c 22

23 The mission: SIS-300 SIS-300 P.Senger D 0, D +, D s +, Λ c, D * J/ψ, Ψʹ SIS-100 SPS Pb+Pb 30 A GeV D 0, D +, Λ c,j/ψ Lynnik et al., Nucl. Phys. A 786 (2007)