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Muon simulations. Anna Kiseleva. Outline. Muon simulations for different collision systems: SIS 300 SIS 100 Muon system optimizations: material of pipe shielding thickness of first absorber alternative solutions of muon system Additional electrons from absorber:
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Muon simulations Anna Kiseleva 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Outline • Muon simulations for different collision systems: • SIS 300 • SIS 100 • Muon system optimizations: • material of pipe shielding • thickness of first absorber • alternative solutions of muon system • Additional electrons from absorber: • comparison of different simulation tools • enhanced "noise" from secondary electrons • Conclusions • Next steps 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Simulations • cbmroot release v.APR08 • signals: multiplicities from HSD, Pluto generator • ω, J/ψ • background: UrQMD central events • Au+Au at 15, 25 and 35 AGeV • Au+Au at 8 AGeV • p+C at 30 GeV • muon magnet • standard STS • standard MuCh • MuCh hit producer without clusters • L1 (STS) and L1/Lit (MuCh) tracking 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Standard Muon Chambers (MuCh) system 5% occupancy for central Au+Au collisions at 25 AGeV w/o shielding Fe 20 20 20 30 35 100 cm min pad 1.42.8 mm2 shielding max pad 44.844.8 mm2 Total number of channels: 480768 ≡ 7.5 λI ≡ 13.5 λI low-mass vector meson measurements (compact setup) 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
background signals ρ ω φ η ηDalitz Au+Au at 25 AGeV* Signal-to- Efficiency Mass Background (%) resolution (S/B) ratio (MeV) ω 0.09 2 10 φ 0.03 4 12 J/ψ 18 13 21 Ψ' 0.8 16 27 background signals J/ψ Ψ' * 10th CBM Collaboration Meeting 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Lit tracking Andrey Lebedev "Track reconstruction in MUCH" Events: URQMD central Au+Au at 25 AGeV + 5 mu+ and 5 mu- in each event (p=1.5..10 GeV/c for compact and p=2.5..25 GeV/c for standard) Compact MuCh: 5 Fe absorbers (125 cm) 10 detector stations Standard MuCh: 6 Fe absorbers (225 cm) 18 detector stations 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Tracking procedures Reconstructed background: L1 Lit Andrey Lebedev "Track reconstruction in MUCH" ω→μ+μ- + central Au+Au collisions at 25 AGeV 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
SIS 100 Au+Au at 8 AGeV p+C at 30 GeV 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Pluto Au+Au at 8 AGeV Compact muon system ω in Au+Au collisions at 8 AGeV min. 9 hits tracks min. 12 hits tracks 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Au+Au at 8 AGeV Results of L1 reconstruction * we can improve results, if we will have ToF pID in MuCh and/or make some simple modifications of CBM setup (see backup slides) 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
p+C at 30 GeV Results of L1 reconstruction ω + central p+C collisions J/ψ + central p+C collisions 1 ω→μ+μ- in 105 central events 4 J/ψ→μ+μ- in 109 central events comparison of HSD and Pluto generated J/psi - see backup slides 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Muon system optimization 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Material of pipe shielding 1 2 3 central Au+Au collisions at 25 AGeV particles/(event×cm2) ―Fe ―W ―Pb + Fe 4 5 particles/(event×cm2) 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Thickness of first absorber 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Motivation: decrease hit density in first detector layers with pipe shielding with pipe shielding 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Particle absorption central Au+Au collisions at 25 AGeV 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Thickness of first absorber (Fe) central Au+Au collisions at 25 AGeV 10 cm Fe 20 cm Fe 30 cm Fe 40 cm Fe 10 cm 100 cm ω→μ+μ- + central Au+Au collisions at 25 AGeV ghosts ! 4 ≥4STS+3MuCh 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
40 20 20 20 25 30 20 20 20 35 20 20 20 30 35 10 20 30 30 35 Alternative muon systems central Au+Au collisions at 25 AGeV 10 cm Fe 20 cm Fe 30 cm Fe 40 cm Fe 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
MuCh 25 30 40 40 25 30 40 40 Nchannels 439 296 → 272 384 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Comparison ―MuCh 20 20 20 30 35 ―MuCh 25 30 40 40 ω→μ+μ- + central Au+Au collisions at 25 AGeV 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Additional electrons from absorber 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Particle rate in first MuCh detector TGEANT3: hadronic process TGEANT4: QGSP_BERT_EMV TFluka 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Particle statistics (per event): 20 cm Fe central Au+Au collisions at 25 AGeV 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Particle statistics (per event): 20 cm Fe central Au+Au collisions at 25 AGeV 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Momentum distributions (20 cm Fe) 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Problems • TFluka is unstable in cbmroot • Present setup of TGEANT4 doesn't include muon production in thick material • Is production of secondary particles in absorber material correctly described? 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Modeling additional electron hits • Create true hit (X0, Y0) • If e, create new point (X0+∆X, Y0+∆Y) • Create noise hit (Xnoise, Ynoise) • Possibility to create more then 1 noise hit from 1 true e e 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Statistics (per event) central Au+Au collisions at 25 AGeV ? 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
MC points ―standard hits additional e: ―+1 ―+2 ―+5 ―+10 Horizontal hit distribution central Au+Au collisions at 25 AGeV 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Invariant mass spectra ω→μ+μ- + central Au+Au collisions at 25 AGeV 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Results of Lit reconstruction ω→μ+μ- + central Au+Au collisions at 25 AGeV 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Background central Au+Au collisions at 25 AGeV +1e +2e +3e 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Conclusions • Simulation tools have been developed to design and optimize CBM muon detection system. • The present muon detector design is tested for different collision systems and beam energies (incl. SIS100). • Simulations with enhanced yield of secondary electrons have been started. Track reconstruction efficiency decrease slightly with increasing number of secondary electrons up to a factor of 3 which corresponds to an increase of total hit density by more than a factor of 2. Simulations with higher hit densities are in progress. 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Next steps • Implementation of: • realistic detector description • different type of the detectors • inefficiency of the detectors • muon trigger • additional secondary electrons with correlated hits in detectors • Muon system optimizations: • number of sensitive layers • thickness of absorbers • optimization tacking into account costs • Test of possible solutions of muon system using LMVM and charmonium simulations 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Thank you for your attention! 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Backup slides 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
m2 = β = γ = m2 = P2 ( - 1) 1 P2 β2 (β × γ)2 L 1 c × t √1 – β2 Au+Au at 8 AGeV Muon system with ToF ToF (80 ps) 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
signal μ background m2 vs. Preco 9 hits 12 hits 9, 12 and 15 hits tracks 15 hits 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Au+Au at 8 AGeV Results after ToF pID 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Au+Au at 8 AGeV Possible modifications for increasing of signal acceptance 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Au+Au at 8 AGeV 1. Decreasing magnet field magnet field: 100% 50% + 12% μω + 22% ω 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Au+Au at 8 AGeV 2. Decreasing the thickness of the absorbers 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
p+C at 30 GeV J/ψ in p+C @ 30 GeV: Pluto and HSD Pluto HSD HSD Pluto 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
p+C at 30 GeV Results of L1 reconstruction 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
p+C at 30 GeV Reconstructed J/ψ Pluto HSD 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna
Comparison of ideal with realistic detector resolution σ =100 μm ω→μ+μ- + central Au+Au collisions segmentation beam energy ── 15 AGeV ── 25 AGeV ── 35 AGeV 12th CBM Collaboration meeting Oct. 13-18 2008, JINR Dubna