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Physics of High Baryon Densities - The CBM experiment at FAIR. Subhasis Chattopadhyay Variable Energy Cyclotron Centre, Kolkata for the CBM collaboration. Outline: CBM physics CBM setup Feasibility studies Detector R&D. CBM. Exploring the QCD Phase diagram. RHIC result:
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Physics of High Baryon Densities - The CBM experiment at FAIR Subhasis Chattopadhyay Variable Energy Cyclotron Centre, Kolkata for the CBM collaboration • Outline: • CBM physics • CBM setup • Feasibility studies • Detector R&D CBM
Exploring the QCD Phase diagram • RHIC result: • new state of matter = perfect liquid? • Tf = 160 – 165 MeV • L-QCD Predictions: • TC = 151 ± 7 ± 4 MeV ( μB=0 ) • (Z. Fodor, arXiv:0712.2930 hep-lat) • TC = 192 ± 7 ± 4 MeV ( μB=0 ) • (F. Karsch, arXiv:0711.0661 hep-lat) • crossover transition at μB=0 • (Z. Fodor, arXiv:0712.2930 hep-lat) • 1. order phase transition • with critical endpoint at μB > 0 High-energy heavy-ion collision experiments: RHIC, LHC: cross over transition, QGP at high T and low ρ Low-energy RHIC:search for QCD-CP with bulk observables NA61@SPS: search for QCD-CP with bulk observables CBM@FAIR: scan of the phase diagram with bulk and rare observables
Questions of QCD What is the equation-of-state of strongly interacting matter? (core collapse supernovae, neutron stars, early universe) What is the structure of strongly interacting matter as a function of T and ρB ? (hot and dense hadronic medium, deconfined phase, phase transitions ?) What are the in-medium properties of hadrons as a function of T and ρB ? (restoration of chiral symmetry ?) After RHIC & LHC we need measurements at large baryon density
What do we need to measure? The equation-of-state at high B collective flow of hadrons particle production at threshold energies (open charm?) Deconfinement phase transition at high B excitation function and flow of strangeness (K, , , , ) excitation function and flow of charm (J/ψ, ψ', D0, D, c) QCD critical endpoint excitation function of event-by-event fluctuations (K/π,...) Onset of chiral symmetry restoration at high B in-medium modifications of hadrons(,, e+e-(μ+μ-), D) CBM: detailed measurement over precise energy bins (pp, pA, AA) FAIR beamenergy range 2-45 AGeV (protons 90 GeV)
Net-baryon densities in central Au+Au collisions at FAIR: consistent picture from transport models Compilation by J. Randrup, CBM Physics Book, in preparation see also I.C. Arsene et al., Phys. Rev. C 75 (2007) 034902 At FAIR energy: large baryon density will be achieved over long time
Elliptic flow at FAIR AMPT calculations: C.M. Ko at CPOD 2007 D J/y ?? Measure flow for all particles over CBM energy range
Probing the quark-pluon plasma with charmonium rescaled to 158 GeV J/ψ ψ' Quarkonium dissociation temperatures: (Digal, Karsch, Satz) sequential dissociation? Measure excitation functions of J/ψ and ψ' in p+p, p+A and A+A collisions !
In-medium modifications D mesons L. Grandchamp, R. Rapp and G. E. Brown, J.Phys. G30 (2004) S1355 A. Andronic, P. Braun-Munzinger, K. Redlich, J. Stachel, arXiv:0708.1488 Mass modifications of D mesons and charmed hyperons affect the ratios ψ'/ψ and charmonium to open charm
hep-ph/0604269 In-medium modifications r mesons Hadronic properties are expected to be affected by the enormous baryon densities → r-meson is expected to melt at high baryon densities Data: In+In 158 AGeV, NA60 Calculations: H.v. Hees, R. Rapp Data: CERES Calculations: R. Rapp no ρ,ω,φ→ e+e- (μ+μ-) data between 2 and 40 AGeV no J/ψ, ψ' → e+e- (μ+μ-) data below 160 AGeV
Multiplicity in central Au+Au collisions W. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl. Phys. A 691 (2001) 745 SIS 100/300 Rare particles with high statistics High beam intensity Interaction rate: 10 MHz Fast detectors/DAQ
The Compressed Baryonic Matter Experiment Transition Radiation Detectors Tracking Detector ECAL Muon detection System Resistive Plate Chambers (TOF) Ring Imaging Cherenkov Detector Silicon Tracking Station Dipole magnet
Benchmark for Vertex-Tracker performance: D mesons and ΛC from Au+Au central collisions at 25 AGeV K- D0 π+ τ = 123 μm/c • Full event reconstruction: • 2 low-mass pixel, 6 micro-strip detectors • proton identification via TOF D and ΛC multiplicity from HSD Hadronic background from UrQMD ΛC → π+K-p τ = 60 μm/c D0
Electron pairs in CBM Central Au+Au collisions at 25 AGeV 25 μm target ρ, ω, φ→ e+e- J/ψ→ e+e- Talk: C. Hoehne, parallel session XXIII Posters: T. Galatyuk K. Antipin
Muon pairs in CBM Central Au+Au collisions at 25 AGeV ρ, ω, φ→ μ+μ- J/ψ, ψ' → μ+μ- Talk: C. Hoehne, parallel session XXIII Poster: A. Kiseleva, P. Bhaduri
Annual yields at RHIC II & LHC 10 weeks CBM Au+Au 25 AGeV from Tony Frawley RHIC Users mtg. B. Jacak QM2006 at LHC: (10-50) x s ~10% of L 25% running time
sensor cable FEE Material: 14 µm Al on 10 µm Kapton 1025 lines, 55 cm long, 100 µm pitch R&D on the Silicon Tracking System First mechanical module prototype, KINR Kiev. System design Design of low-mass detector modules Micro-strip detector prototype CBM01, Cooperation GSI-CIS. Front-end electronics prototyping with n-XYTER chip, GSI-DETNI. • R&D effort: • micro-strip detector modules • low-mass mechanics • sectors of different strip lengths • r/o electronics outside aperture • 10 MHz full-frame readout R&D on ultra-low-mass readout cables. Cooperation with SESRTIIE Kharkov. Poster: J. Heuser
Muon detection system 20 20 20 30 35 cm Chambers: high resolution gas detectors (major Indian participation) Challenges: High Rate High density Large background 260cm Fe Fe Fe Fe Fe 5 cm 0 cm 102.5 cm
GEM (fast high resolution detector) under test at VECC-Kolkata Gas Inlet GEM assembly housed in ~60 cm x ~30 cm box Resistive chain biasing Gas: Ar/CO2-70/30 Source: Ru106(ß) mesh – a 5-10 micron thick nichrome wire source 6 mm holes in the plexiglass top cover for Source.
High speed DAQ Online Event selection Poster: W. Mueller Self-triggered fast readout chip for double-sided Silicon Strip detectors and GEM detectors (128 channels, 32 MHz) under test in the GSI Detlab.
Summary and Conclusions CBM • Exploration of QCD phase diagram at high baryon densities • Precision measurement of excitation functions including rare probes • in pp, pA and AA • CBM: Next generation heavy ion experiment at reaction rates up to 10 MHz • Fast detectors, High speed DAQ, online event selection • Simulation shows the feasibility of rare probe measurements • Detector R&D in progress
CBM Collaboration : 51 institutions, ~ 400 members Romania: NIPNE Bucharest Russia: IHEP Protvino INR Troitzk ITEP Moscow KRI, St. Petersburg Kurchatov Inst., Moscow LHE, JINR Dubna LPP, JINR Dubna LIT, JINR Dubna MEPHI Moscow Obninsk State Univ. PNPI Gatchina SINP MSU, Moscow St. Petersburg P. Univ. Ukraine: Shevshenko Univ. , Kiev Croatia: RBI, Zagreb Split Univ. China: CCNU Wuhan USTC Hefei Cyprus: Nikosia Univ. Czech Republic: CAS, Rez Techn. Univ. Prague France: IPHC Strasbourg Hungaria: KFKI Budapest Budapest Univ. Germany: Univ. Heidelberg, P.I. Univ. Heidelberg, KIP Univ. Frankfurt Univ. Mannheim Univ. Münster FZ Dresden GSI Darmstadt Poland: Jag. Univ. Krakow Warsaw Univ. Silesia Univ. Katowice AGH Krakow Portugal: LIP Coimbra 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 IlT Kharagpur Korea: Korea Univ. Seoul Pusan National Univ. Norway: Univ. Bergen Supported by EU FP6 CBM Collaboration Meeting in Strasbourg Sept. 2006
25 AGeV central AuAu Phase space coverage • r-meson • 25 AGeV beam energy: midrapidity = 2 • electrons: full coverage • muons: acceptance forward shifted, weak for low-pt electrons muons