Di-hadron correlation and Mach-like Di-hadron correlation and Mach-like cone structures in partonic/hadronic cone structures in partonic/hadronic transport model transport model

Di-hadron correlation and Mach-like Di-hadron correlation and Mach-like cone structures in partonic/hadronic cone structures in partonic/hadronic transport model transport model

Guo-Liang MaGuo-Liang Ma Guo-Liang MaGuo-Liang Ma

Background introductionBackground introduction Model introductionModel introduction Analysis methodAnalysis method Results and discussionsResults and discussions ConclusionConclusion

Collaborators: S. Zhang, Y. G. Ma, H. Z. Huang, X. Z. Cai, Collaborators: S. Zhang, Y. G. Ma, H. Z. Huang, X. Z. Cai, J. H. Chen, Z. J. He, J. L. Long, W. Q. Shen, X. H. Shi et al.J. H. Chen, Z. J. He, J. L. Long, W. Q. Shen, X. H. Shi et al.

Shanghai Institute of Applied Physics Shanghai Institute of Applied Physics   

nucl-th/0601012Guo-liang Ma Hard Probes Asilomar 2006

Di-hadron correlations

pT(assoc) > 2 GeV/c

pT(assoc) > 0.15 GeV/c

4 <

p T(t

rig)

< 6

GeV

/c

Soft associated Soft associated particlesparticles →→ enhancementenhancement

Hard associated Hard associated particles particles →→ suppressionsuppression

Associated particlesOn away side:

Soft Associated particles on Away side (thermalization)

near sidenear side

away side

thermalization???thermalization???

BROADENEDBROADENED

<pT > from away jets

<pT> from medium decay

SOFTENED

SOFTENED

What happens to a hard probe that traverses a colored medium?

soften + broaden =?= thermalizationthermalization

Mach-like cone Structurenucl-ex 0510055

PHENIX Preliminary

nucl-ex 0507004

2.5

<p

Ttrigg

er < 4

.0 G

eV

/c x

1.0

<p

Tasso

c<

2.5

Ge

V/c

Split parameter D

PHENIX QM05

Wake Effect or “sonic boom” Wake Effect or “sonic boom”

nucl-th/0406018 Stöeckerhep-ph/0411315 Casalderrey-Solana,Shuryak,Teaneynucl-th/0503028 A. K. Chaudhurihep-ph/0503158 Muller,Ruppert

hep-ph/0411341 Armesto,Salgado,Wiedemann

Correlation of Jet with flowing medium Correlation of Jet with flowing medium

Cherenkov gluon radiation Cherenkov gluon radiation

PRL 96, 172302 (2006) Koch, Majumder, X.-N. Wang

Possible interpretations of mach-like cone structure

Θemission= arccos (cs/c)

Θemission= arccos (1/n(p))

AMPT model

(1) Default AMPT Model (2) Melting AMPT Model

a multi-phase transport model

(1) Get raw correlation signal in same event.

(2)Get respective background by mixing events in same centrality.

(3)Get correlation by removing background with ZYAM method.

Mix-event Technique

-1 0 1 2 3 4 50

2

4

6

8460

470

480

490

500

510

520

530

1/N

trig

dNch

/d

20-40%

20-40%

PT

trig 3-6GeV/c ,PT

asso 0.15-3GeV/c same event mix event

Background Subtracted signal

correlationscorrelations from AMPT from AMPT((3<pT

trigger<6GeV/c ,0.15<pTassoc<3GeV/c)

(1) ▲melting version after hadronic rescattering(2) ● melting version before hadronic rescattering(3) ◆ default version after hadronic rescattering(4)★ default version before hadronic rescattering(5) ■ Star Data 0-5% (4-6)*(0.15-4)GeV/c factor=1.58

Au+Au 200GeV (0-10%)

2 4 6 8 10 120

2

4

6

8

10

12

14

16

18

20

0 1 2 3 410-3

10-2

10-1

100

101

102

PT

trig 3-6GeV/c (AMPT) near away

PT

trig 4-6GeV/c ( STAR data X factor=1.58) near away

impact parameter b (fm)

asso

ciat

ed N

hadr

on

(a)

PT

trig 4-6GeV/c (STAR data X factor=1.58)

0-5% away 0-5% near X 0.1

(b)

PT

trig 3-6GeV/c (AMPT) 0-5% away 0-5% near X 0.1

dNha

dron

/dP

(G

eV/c

)-1

PT (GeV/c)

-2 -1 0 1 20.5

0.6

0.7

0.8

0.9

1.0 AMPT data PT

trig 3-6GeV/c away

STAR data PT

trig 4-6GeV/c away

(0-10%)

<p T>

(Gev

/c)

- (rad)

(c)

0 2 4 6 8 10 12 14

0.7

0.8

0.9

1.0(d) P

T

trig 3-6GeV/c(AMPT) away

PT

trig 4-6GeV/c(STAR data) away

impact parameter b (fm)

<P

T> (

GeV

/c)

Jet remnants’ characters in AMPT Au+Au 200GeV Melting AMPT model

-0.10.00.10.20.30.40.50.60.70.8

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0 1 2 3-0.1

0.0

0.1

0.2

0.3

0.4

0.5

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

10-20% (2.5-4)X(1-2.5)GeV/c melting version after hadron rescattering factor=1/1.75 melting version before hadron rescattering factor=1/1.75 default version after hadron rescattering factor=1/0.7 PHENIX data 10-20% faxtor=1.58

1/N

trigd

N/d

20-40% (2.5-4)X(1-2.5)GeV/c melting version after hadron rescattering factor=1/1.75 melting version before hadron rescattering factor=1/1.75 default version after hadron rescattering factor=1/0.7 PHENIX data 20-40% factor=1.58

1/N

trigd

N/d

(rad)

40-90% (2.5-4)X(1-2.5)GeV/c melting version after hadron rescattering factor=1/1.4 melting version before hadron rescattering factor=1/1.4 default version after hadron rescattering factor=1/0.7 PHENIX data 60-90% factor=1.58

1/N

trigd

N/d

0-10% (2.5-4)X(1-2.5)GeV/c melting version after hadron rescattering factor=1/4.2 melting version before hadron rescattering factor=1/4.2 default version after hadron rescattering factor=1/1.75 default version before hadron rescattering factor=1/1.75 PHENIX data 0-5% factor=1.58

1/N

trigd

N/dMach-like cone Mach-like cone

Structure in Structure in AMPT modelAMPT model correlations in Au+Au 200GeV correlations in Au+Au 200GeV ((2.5<pT

trigger<4GeV/c ,1<pTassoc<2.5GeV/c)

Mach-like cone Mach-like cone Structure in Structure in AMPT modelAMPT model correlations in Au+Au 200GeV correlations in Au+Au 200GeV ((2.5<pT

trigger<4GeV/c ,1<pTassoc<2.5GeV/c)

2 4 6 8 10 120.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

AMPT PT

trig 2.5-4(GeV/c),PT

associated 1-3.(GeV/c) melting version after hadronic rescattering default version after hadronic rescattering

exp. data PT

trig 2.5-4(GeV/c),PT

associated 2-3(GeV/c)split

ing

para

met

er D

(ra

d)

impact parameter b (fm)

D

Correlations between forward- and mid-rapidity in d+Au collisions

STAR Preliminary

See Fuqiang’s talk

Mid-rapidity

Forward-rapidity

trig.

asso.

Three-particle correlations in AMPT

mix-event technique background subtracted

3-particle correlation signal

((2.5

<pTtri

gger <

4GeV

/

c ,1<

p Tas

soc <2

.5GeV

/c)

Three-particle correlation centrality dependence3-particle correlation

density definition:

region

region

dd

ddddNd

21

2121

2

Parton cascade effect on 2- and 3- particle correlation

(1)Hadronic rescattering (1)Hadronic rescattering mechanism also can mechanism also can produce produce 2- and 3-particle 2- and 3-particle correlation, but it can correlation, but it can not give big enough not give big enough splitting parameters. splitting parameters. (2) Parton cascade (2) Parton cascade mechanism is essential mechanism is essential for describing the for describing the amplitude ofamplitude ofexperimental mach-like experimental mach-like structure.structure.

Conclusion1) Di-hadron correlations can be produced by a multi-

phase transport model(AMPT).

2) Mach-like structure is born in the partonic process and further developed in hadronic rescattering process.

3) hadronic rescattering mechanism can produce di-hadron correlation, but it can not give big enough splitting parameters.

4) Cone , deflected and center 3-particle correlations all exist in the central Au+Au collisions, however center 3-particle correlation become more dominant with the decreasing of Npart .

Thanks for

your attentions!