Slide Title

1
Di-hadron correlation and Mach-like cone
structures in partonic/hadronic transport model
Guo-Liang Ma
Shanghai Institute of Applied Physics  
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.

• Background introduction
• Model introduction
• Analysis method
• Results and discussions
• Conclusion

nucl-th/0601012
Guo-liang Ma Hard Probes Asilomar 2006
2
Di-hadron correlations
3
Soft Associated particles on Away side
(thermalization)
What happens to a hard probe that traverses a
colored medium? soften broaden ?
thermalization
4
Mach-like cone Structure
nucl-ex 0510055
nucl-ex 0507004
2.5ltpTtrigger lt 4.0 GeV/c x 1.0ltpTassoclt2.5 GeV/c
PHENIX Preliminary
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Split parameter D
PHENIX QM05
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Possible interpretations of mach-like cone
structure
Wake Effect or sonic boom
Temission arccos (cs/c)
nucl-th/0406018 Stöecker hep-ph/0411315
Casalderrey-Solana,Shuryak,Teaney nucl-th/0503028
A. K. Chaudhuri hep-ph/0503158 Muller,Ruppert
Cherenkov gluon radiation
Temission arccos (1/n(p))
PRL 96, 172302 (2006) Koch, Majumder, X.-N. Wang
Correlation of Jet with flowing medium
hep-ph/0411341 Armesto,Salgado,Wiedemann
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AMPT model
a multi-phase transport model
(2) Melting AMPT Model
(1) Default AMPT Model
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Mix-event Technique

• (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.

Background Subtracted signal
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?? correlations from AMPT (3ltpTtriggerlt6GeV/c
,0.15ltpTassoclt3GeV/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 factor1.58
AuAu 200GeV (0-10)
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Jet remnants characters in AMPT
AuAu 200GeV
Melting AMPT model
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Mach-like cone Structure in AMPT model ??
correlations in AuAu 200GeV (2.5ltpTtriggerlt4GeV/c
,1ltpTassoclt2.5GeV/c)
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Correlations between forward- and mid-rapidity
in dAu collisions
STAR Preliminary
See Fuqiangs talk
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Three-particle correlations in AMPT
mix-event technique
(2.5ltpTtriggerlt4GeV/c ,1ltpTassoclt2.5GeV/c)
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Three-particle correlation centrality dependence

• 3-particle correlation
• density definition

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

• Di-hadron correlations can be produced by a
  multi-phase transport model(AMPT).
• Mach-like structure is born in the partonic
  process and further developed in hadronic
  rescattering process.
• hadronic rescattering mechanism can produce
  di-hadron correlation, but it can not give big
  enough splitting parameters.
• Cone , deflected and center 3-particle
  correlations all exist in the central AuAu
  collisions, however center 3-particle correlation
  become more dominant with the decreasing of Npart
  .

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Thanks for your attentions!