Performance Evaluation for Open Charm and Beauty Measurement at LHC ALICE PID capability from λ and K s 0 measurement at LHC ALICE 筑波大学数理物質科学研究科 Kengo Watanabe for the ALICE Collaboration

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

To provide constrains on parton energy loss at the very early stage of the collisions (time-scale ~ 1/m Q < τ QGP ~ 10 fm at LHC) c,b have long lifetime (> τ QGP ) and can probe the bulk, strongly interacting phase study of final state effects Elliptic flow Open Charm and Open Beauty Measurement V 2 provides information on the opacity of the medium

Heavy flavour measurements in ALICE Weak decaying charm and beauty D + m ~ 1869 MeV, cτ ~ 312 μm D 0 m ~ 1865 MeV, cτ ~ 123 μm D s + m ~ 1968 MeV, cτ ~ 147 μm B + m ~ 5279 MeV, cτ ~ 501 μm B 0 m ~ 5279 MeV, cτ ~ 460 μm B s 0 m ~ 5370 MeV, cτ ~ 438 μm B c + m ~ 6400 MeV, cτ ~ 100~200 μm Primary vertex Decay vertex 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 Secondary tracks will be reconstructed with help of the ITS,TPC,TRD and TOF

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 K s 0 measurements invaliant mass, S/N,S*S/N PID cut, Pt dependence ALICE detector performance

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

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

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 PID Summary Open charm and Open Beauty production are difficult for my data ALICE performance using K s 0 and λ

λ & K s 0 invaliant mass (ITS && TPC) or TOFITS or TPC or TOFITS or TPC or TOF mix λ->p+π (unlike pair) K s 0 ->π+π (unlike pair)

S/N (ITS && TPC) or TOF ITS or TPC or TOF ITS or TPC or TOF mix S/N= background signal λ Ks0Ks0 S*S/N = S= S/N= S*S/N= S/N= S=9533 S*S/N= S/N= S= S*S/N= S/N= S=9515 S*S/N= S/N= S= S*S/N= S=6714

Pt cut 0<Pt< <Pt<0.50.5<Pt< <Pt< <Pt<1.51.5<Pt<2.02.0<Pt<2.52.5<Pt<3.0 λ

Pt dependence of S/N (ITS && TPC) or TOF Pt (GeV/c) ITS or TPC or TOF ITS or TPC or TOF mix S/N TOF ITS,TPC Ks0Ks0 λ TOF ITS,TPC S/N its ≒ S/N tpc PID capability of ITS and TPC is certain

Particle identification of ALICE central detector (ITS,TPC,TOF) using simulation data S/N, S*S/N from λ and K s 0 mass spectrum S/N show good PID capability of ITS and TPC S*S/N show miss ID particle can be ignored Summary ALICE will be able to Identified rare particle, D,B,J/Ψ,Υ with help of vertex detector and PID detector