Performance Evaluation for Open Charm and Beauty Measurement at LHC ALICE

1. Performance Evaluation for Open Charm and Beauty Measurement at LHC ALICE PID capability from λ and Ks0 measurement at LHC ALICE 筑波大学数理物質科学研究科 Kengo Watanabe for the ALICE Collaboration

2. ALICE Detector Over View TRD TOF HMPID ITS PMD Muon Spectrometer TPC PHOS

3. Open Charm and Open Beauty Measurement • To provide constrains on parton energy loss at the very early stage of the collisions (time-scale ~ 1/mQ < τQGP ~ 10 fm at LHC) • c,b have long lifetime (> τQGP) and can probe the bulk, strongly interacting phase study of final state effects • Elliptic flow V2 provides information on the opacity of the medium

4. Heavy flavour measurements in ALICE Weak decaying charm and beauty B+ m ~ 5279 MeV, cτ ~ 501 μm B0 m ~ 5279 MeV, cτ ~ 460 μm Bs0 m ~ 5370 MeV, cτ ~ 438 μm Bc+ m ~ 6400 MeV, cτ ~ 100~200 μm D+ m ~ 1869 MeV, cτ ~ 312 μm D0 m ~ 1865 MeV, cτ ~ 123 μm Ds+ m ~ 1968 MeV, cτ ~ 147 μm Heavy flavour weak decay track is displaced from primary vertex by ~ few 100 μm Decay vertex will be observed with help of the ITS Inner Tracking System contain 6 silicon layers silicon pixel detector reconstruct secondary vertex Decay vertex Secondary tracks will be reconstructed with help of the ITS,TPC,TRD and TOF Primary vertex

5. Outline • Simulation Data 0.9GeV minimum bias event PYTHIA, ALICE GEANT • Reconstruction all simulation data were reconstructed -> track, vertex ,signal in each detector • PID (ITS,TPC,TOF) • λ and Ks0 measurements invaliant mass, S/N,S*S/N PID cut, Pt dependence ALICE detector performance

6. Particle Identification in ALICE 1 cut (combined bands) cut (track length = 0) All signal ITS K p π TPC p K e π

7. Particle Identification in ALICE 2 Before cut After cut p K π

8. PID Summary • Input data 0.9 TeV pp minimum bias. 1 M events reconstructed data (ALICE official data) • Electron data 3000 events (NO TRD PID) TRD show other particle contamination in TPC electron band Open charm and Open Beauty production are difficult for my data ALICE performance using Ks0 and λ

9. λ & Ks0invaliant mass (ITS && TPC) or TOF ITS or TPC or TOF ITS or TPC or TOFmix λ->p+π (unlike pair) Ks0->π+π (unlike pair)

10. signal S/N background ITS or TPC or TOFmix ITS or TPC or TOF (ITS && TPC) or TOF S=9515 S=9533 S=6714 S/N= 1.60 S/N= 1.59 λ S/N=1.74 S*S/N=11665.7 S*S/N=15232.5 S*S/N=15235.9 S=126290 S=226329 S=226385 Ks0 S/N= 1.19 S/N= 1.15 S/N= 1.15 S*S/N = 260364 S*S/N=149771 S*S/N=260288

11. Pt cut 0<Pt<0.25 0.25<Pt<0.5 0.5<Pt<0.75 0.75<Pt<1.0 λ 1.0<Pt<1.5 1.5<Pt<2.0 2.0<Pt<2.5 2.5<Pt<3.0

12. Pt dependence of S/N S/Nits ≒ S/Ntpc (ITS && TPC) or TOF PID capability of ITS and TPC is certain ITS or TPC or TOF ITS or TPC or TOFmix Ks0 λ S/N S/N TOF TOF ITS,TPC ITS,TPC Pt (GeV/c) Pt (GeV/c)

13. Summary • Particle identification of ALICE central detector (ITS,TPC,TOF) using simulation data • S/N, S*S/N from λ and Ks0 mass spectrum • S/N show good PID capability of ITS and TPC • S*S/N show miss ID particle can be ignored ALICE will be able to Identified rare particle, D,B,J/Ψ,Υ with help of vertex detector and PID detector