k ± k ± hbt study with hmpid - status report -

Jungyu Yi

Pusan National UniversityKo-ALICE meeting

K±K± HBT STUDY WITH HMPID- STATUS REPORT -

Ko-ALICE meeting, 20130205 2

Motivation

Historical review• In 1950s, Hanbury-Brown &

Twiss – For Improving of Resolution Power

of Michelson Interferometry: [Phil.Mag.45, 663 (1954)]

– Astronomical Application :[Nature 178, 1046 (1956)] A Test of a New Type of Stellar Interferometer on Sirius

• Particle Physics application– G. Goldhaber, S. Goldhaber, W. Lee,

& A. Pais : [Phys.Rev.120,300 (1960)] Influence of Bose-Einstein Statistics on the Antiproton-Proton Annihilation Process

– GGLP : Bose-Einstein Correlation

HMPID • Contribution of the HMPID

detector to the high-pT physics at LHC[D.Di Bari et al. arXiv:0801.2695v1, 2008]– “ Final-state information of heavy-

ion collisions is more directly accessed by interferometric methods, such as the Hanbury-Brown and Twiss (HBT) measurement.”

– “At LHC, due to the high multiplicity, event-by-event HBT could be performed. To achieve event- by-event HBT measurements, 3σ separation in particle identification is required. The HMPID can contribute in the high-pT region: to π±π±, K±K± and p±p± HBT measurements.

JunGyu Yi <[email protected]>

3

Analysis Concept

JunGyu Yi <[email protected]> Ko-ALICE meeting, 20130205

for analysis,

A (q) : pair distribution in momentum difference q = p2 – p1 for pairs of particles from the same event.B (q) : the corresponding distribution for pairs of particles from different events.

Compares relative momenta of identical particles to determine information about

space-time geometry of source

~ 1/R

(: transverse momentum)Rside : related geometrical transverse sizeRlong : related longitudinal extentRout : related to emission duration

The correlation function for Gaussian source( 1D parameterization )

(3D parameterization )

)2()1()2|1(

PPPC

Bose-Einstein correlation


HMPID layout


p and K up to 3 GeV/c p up to 5 GeV/c, track-by-track basis.

~ 5% acceptance w.r.t Central barrel detectors


HMPID Analysis task


AliHMPIDAnalysisTask.cxx/.hincludes,

– AliESDtrack.h– AliPID.h– AliCentrality.h– AliPIDResponse.h– Tree– TreeEvt

run ‘AnalysisTrainHMPID.C’ includes,– AddTaskPhysicsSelection.C– AddTaskCentrality.C– AddTaskESDFilter.C– AddTaskJets.C– AddTaskPIDResponse.C– AddTaskHMPID.C

for event


hmpidouput.root :: HMP X,Y • Aliroot::v5-03-57-AN• LHC11h pass2• example : run_169504, events: 145654


There was problems in HMPID- Module 1 , 4, 6- It’s known, can affect

the acceptance

7

Cherenkov Angle vs. momentum


AliPID::kMuon, Prob1>0.7

AliPID::kPion, Prob2>0.7 AliPID::kKaon, Prob3>0.7 AliPID::kProton, Prob4>0.7

AliPID::kElectron, Prob0>0.7

8

Total and Kaon Multiplicity : e-by-e


track->GetNcls(1) >70

DCA < 2 [cm] MIP charge > 100 &&

probsHMP[3]>0.7

track->GetNcls(1) >70

DCA < 2 [cm] MIP charge > 100


Outlook• Kaon PID with HMPID in PbPb √sNN = 2.76 TeV

– HMPID framework study : partially done– HMPID Track/PID quality study for PbPb

• At least 1 Kaon track : for bkg. , event mixing• At least 2 Kaon track : for Signal

– Analysis algorithms, Code development• correlation signal construction• event mixing

• PWGCF - femtoscopy framework study

• Goal– Preliminary ‘Correlation function (qinv)’ in this winter.

• Welcome advice, comments, suggestions!!JunGyu Yi <[email protected]>


BACKUP



Bose-Einstein Correlation (1)


p1

p2

r1‘

r2‘

r1

r2

Bose-Einstein Correlation Function C2 =

P(p1,p2)P(p1)P(p2)

= 1+drS(K,r)eiqr 2

drS(K,r) 2

A(p1,r1)eij(r1)eip1(r1-r‘1)A(p2,r2)eij(r2)eip2(r2-r‘2)

= Yd

A(p1,r2)eij(r2)eip1(r2-r‘1)A(p2,r1)eij(r1)eip2(r1-r‘2) = Yc

P(p1,p2) = dr1dr2r(r1)r(r2)|F|2

{Yd + Yc} = eij(r1)eij(r2)F(p1p2:r1r2 r1‘r2‘)

12

q = p1 - p2 K= 0.5(p1 + p2) ; r = r1 - r2

= P(p1)P(p2) + | dreiqrr(r)A2(K,r)|2


Total identical pions pairs = 800 *106 in 60*106 p-p 7 TeV MB events

0.13 GeV/c < KT < 0.7 GeV/c

22,1, TT

T

ppk

Identical kaons pairs yield in HMPID acceptance in PbPb data



66

66

777

1025.320*

10601010*

201*

201*)10800(

****

TeVpp

lPbPbcentra

TeVpp

lPbPbcentraacceptacceptTeVpplPbPbcentra yields

yieldsKNeventsNeventsHMPHMPNpairsNpairsK

Identical kaons pairs yield in HMPID acceptance in PbPb data



Total statistic collected up to now 2010• pp 7 TeV, LHC10b and LHC10c (pass3): ≈ 80* millions of MB events, new tracking;

• pp7 TeV, LHC10d (pass2): ≈ 200 millions of events, old tracking;

• pp 7 TeV, LHC10e (pass2): ≈ 200 millions of events, old tracking;

• PbPb 2.76 ATeV, LHC10h (pass2): ≈ 10* millions of MB events , old tracking;

2011• pp 2.76 TeV, LHC11a (pass3): ≈ 50* millions of MB events, new tracking;

• pp 7 TeV, LHC11b (pass1) : ≈ 50 millions of events, old tracking;

• pp 7 TeV LHC11c (pass1): ≈ 100 millions of events, half old tracking, half new tracking;

• pp 7 TeV LHC11d (pass1): ≈ 20 millions of events, new tracking;



2011• pp 7 TeV, LHC11e (pass1): ≈ 40 millions of events, new tracking;

• PbPb 2.76 ATeV, LHC11h: ≈ 10* millions of central events, ≈ 10 millions of semi-central events, few millions of MB events, new tracking.

2012 (MB events fraction rather small)• pp 8 TeV, LHC12a (pass1): ≈ 50 millions of events, new tracking;

• pp8 TeV, LHC12b (pass1): ≈ 70 millions of events, new tracking;

• pp8 TeV, LHC12c (cpass1): ≈ 30 millions of events, new tracking;

• pp8 TeV, LHC12d (pass1): ≈ 30 millions of events, new tracking;

• pp8 TeV, LHC12f (pass1): ≈ 10 millions of events, new tracking;

• pp8 TeV, LHC12g and LHC12h (cpass1): ≈ 6 millions if events, new tracking;

• …………………………………………………?

Total statistic collected up to now



• Total p-p 8 TeV MB events: ≈ 20*106?

• Total p-p 7 TeV MB events: ≈ 800*106

• Total p-p 2.76 TeV MB events: ≈ 50*106

• Total Pb-Pb 2.76 ATeV events: 10*106 MB, 10*106 central (0-10%), 10*106 semi central (10-50%)

Total statistic collected up to now


k ± k ± hbt study with hmpid - status report -

Documents

ejungyu yi koalice meeting

event hbt measurements

kaon track

track basis

event mixingat

hmpid detector

pp hbt measurements

twiss hbt measurement