Data Analysis Practicelooking for Φ(1020)

2006. 12. 12Nuclear Physics Ⅲ

Kyung-Eon,Choi

Contents

• NA49 detector • Φ(1020) study• Data Set • Analysis strategy• Analysis procedure• Find Φ peak• Others..

NA49 Detector Setup

Main TPC

Vertex TPC 1

Vertex TPC2

Beam

Φ (1020)

• Mass m = 1019.456 +- 0.020 MeV

• Full width Γ = 4.26 +- 0.05 MeV

< Decay mode >K+K- (49.1 +- 0.6 %) (34.0 +- 0.5 %)SLKK 00

My Way ~!!

Data Set

• Run Type – 01I : Pb+Pb 160 AGeV central 256 TB

• Event– Total event : 2,968,504– Used event :

• Track – Accepted Track :

Analysis Strategy

Draw dEdx-p histogram Using dEdx-m histogram for cut

Slice dEdx-p histogram

Fit sliced histogram & Save parameters

Mark with a dot using Saved parameters

(dEdx-βγ graph) Fit with Bethe-Bloch formula

Use parameters as cuts

Mix particles using cuts & Mixing method

dEdx - p - m Histogram

dEdx - p - m (kaon cut)

dEdx - p - m (proton cut)

dEdx - p

Slice

dEdx - fit

Cuts• EventCut

– Vertex X & Y: -1 ~ 1 cm– Vertex Z : -582 ~ -580 cm– Multiplicity : 700 ~ 1500

• K+ Cut (PosParticleList)– Charge : 1– Bx (impact parameter) : -5~5 cm– By : -2 ~2 cm– Momentum Range : 3<p<100– Mass2 : 0.12 < m2 < 0.36– SetDedxSigma : 0.9 ~ 1.03

• K- Cut (NegParticleList)– Charge : -1– Bx (impact parameter) : -5~5 cm– By : -2 ~2 cm– Momentum Range : 3<p<100– Mass2 : 0.12 < m2 < 0.36– SetDedxSigma : 0.9 ~ 1.03

I don’t need PID..

Event Cut

Track Cut

Result

Compare with yoo’s result

Mean Sigma

Choiku’s

1018.35 MeV

3.9 MeV

Yoo’s 1018.10 MeV

3.3 MeV

ParticleDatabo

ok

1019.456 MeV

4.26 MeV

Another interest ~!! Kaon(Strangeness) Suppression??

or Strangeness Enhancement??