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Two- and Three-particle Correlations in a Partonic Transport Model Y.G. Ma, G.L. Ma, S. Zhang, X. Z. Cai, H. Z. Huang et al. Shanghai Institute of Applied Physics, CAS Background introduction Model introduction Analysis method Results and discussions Conclusions G.L. Ma, S. Zhang, YGM et al., Phys Lett B 641, 362 (2006) G.L.Ma, YGM, S. Zhang et al., arXiv:nucl-th/0608050, sub to PLB G.L.Ma, S. Zhang, YGM et al., arXiv:nucl-th/0610088, sub to APS (1 Di-hadron correlations pT(assoc) > 2 GeV/c Associated particles On away side: Hard associated particles → suppression pT(assoc) > 0.15 GeV/c Soft associated particles → enhancement (2 t Associated particles on Away side (thermalization) near side away side SOFTENED BROADENED thermalization??? What happens to a hard probe that traverses a colored medium? softened + broadened =?= thermalized (3 Mach-like Structures PHENIX PRL 97, 052301 (2006) NPA 774, 581 (2006) (4 Possible interpretations of Mach-like structures Wake Effect or “sonic boom” Θemission= arccos (cs/c) NPA 750, 121 (2005) Stöecker hep-ph/0411315, hep-ph/0602183 Casalderrey-Solana PLB 618, 123 (2005) J. Ruppert PRC 73, 011901(R) (2006) T. Renk PRL 97, 062301(2006) A. K. Chaudhuri Cherenkov gluon radiation Θemission= arccos (1/n(p)) PRL 96, 172302 (2006) Koch, Majumder, X.-N. Wang PLB 630, 78 (2005) I. Vitev NPA 767, 233 (2006) I.M. Dremin Correlation of Jet with flowing medium PRC 72, 064910 (2005) Armesto (5 AMPT model a multi-phase transport model (by C. M. Ko and Z. W. Lin et al.) (1) Default AMPT Model (2) Melting AMPT Model (6 Mixing-event Technique correlation signal in same event. (2)Get respective background by mixing events in same centrality. (3)Get correlation by removing background with ZYAM method. 1/NtrigdNch/d (1) Get raw 530 520 510 500 490 480 470 4608 trig PT 3-6GeV/c ,PT same event asso 0.15-3GeV/c mix event 20-40% 6 20-40% 4 2 0 -1 Background Subtracted signal 0 1 2 3 4 5 (7 correlations from AMPT (3<pTtrigger<6GeV/c ,0.15<pTassoc<3GeV/c) Au+Au 200GeV (0-10%) AMPT 0-10%,(3-6) x (0.15-3)GeV/c melting version after hadronic rescattering melting version before hadronic rescattering default version after hadronic rescattering default version before hadronic rescattering Star Data 0-5% (4-6) x (0.15-4)GeV/c factor=1.58 1/NtrigdN/d (1) ▲melting version 8 after hadronic 7 rescattering (2) ● melting version 6 before hadronic rescattering 5 (3)◆ default version 4 after hadronic rescattering 3 (4)★ default version before hadronic 2 rescattering 1 (5) ■ Star Data 0-5% (4-6)*(0.154)GeV/c0 factor=1.58 -1 0 1 2 3 4 5 (rad) (8 Mach-like Structures in AMPT model 0.5 1/NtrigdN/d 1.0 0.9 0.8 0.7 0.6 0.4 0.3 0.2 associated AMPT PT 2.5-4(GeV/c),PT 1-3.(GeV/c) melting version after hadronic rescattering default version after hadronic rescattering trig associated exp. data PT 2.5-4(GeV/c),PT 2-3(GeV/c) 2 4 6 8 10 impact parameter b (fm) D 0.2 0.1 12 -0.1 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 -0.1 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 -0.1 0.5 1/NtrigdN/d 1/NtrigdN/d 1.1 1/NtrigdN/d spliting parameter D (rad) 1.2 0.5 0.3 0.0 correlations in Au+Au 200GeV (2.5<pTtrigger<4GeV/c ,1<pTassoc<2.5GeV/c) trig 0.4 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 0.4 0.3 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 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 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 0.2 0.1 0.0 -0.1 0 1 2 (rad) (9 3 Is there conical flow? near near 3-4 GeV/c 2 trigger Medium 1-2 GeV/c assoc assoc Medium away 3-particle correlation mach cone away di-jetsnear soft bkgd 1 2 hard-soft-corr + soft-bkgd. flow modulated background: 1 2v2trig v2(1) cos[2(1 trig )] 2v2trig v2(2) cos[2(2 trig )] 2v2(1) v2(2) cos[2(1 2 )] Medium away deflected jets 1 soft-soft-corr in underlying event. Three-particle correlations in AMPT mix-event technique background subtracted 3-particle correlation signal (10 The Npart dependences of three-particle correlations 3-particle correlation density definition: region d 2N d1d2 d1d2 d d 1 2 region (11 What happens for p+p? No Mach-cone behavior! Correlations between forward- and mid-rapidity in d+Au collisions STAR Preliminary Mid-rapidity trig. asso. Forward-rapidity Parton cascade effect on 2- and 3- particle correlations (1)Hadronic rescattering mechanism also can produce 2- and 3-particle correlations, but it can not give big enough splitting parameters. (2) Parton cascade mechanism is essential for describing the amplitude of experimental mach-like structure. (12 Time Evolution of Mach-like Structures in AMPT model 0.7 melting AMPT model without hadronic rescattering (10mb) central 0-10%, |y|<1.0 (2.5-4.0)X(1.-2.5)GeV/c 0.5 1.6 1.5 assoc 0.4 0.3 1/NtrigdN hadron 1/NtrigdN assoc /d lifetime (fm/c)= 0.5 1.0 melting AMPT model without hadronic rescattering (10mb) central 0-10%, |y|<1.0 (2.5-4.0)X(1.-2.5)GeV/c (b) 0.2 lifetime (fm/c)= 2.0 2.5 4.0 5.0 /d 0.6 2.0 hadron (a) 1.2 3.0 0.8 0.4 0.1 0.0 0.0 -1 0 1 2 3 4 (Rad) Lifetime parton cascade hadronic rescattering 5 6 -1 0 1 2 3 4 5 6 (Rad) At least a lifetime of partonic matter of 1.5 fm/c is needed for the birth of Machlike structures for 10mb. (13 Partonic Mach-Like Shock Waves ? Au+Au 200GeV (0-10%) (14 pT dependences of Mach-like structures pT-dependent Mach-like shock waves (15 η dependences of Mach-like structures PHOBOS ? √ ? ? ? ? (16 Conclusions and Outlook Conclusions: 1) Partonic Mach-like shock waves are born in the strong parton cascade and further developed in hadronic rescattering process. 2) Hadronic rescattering mechanism can produce similar correlation, but it can not give big enough splitting parameters and correlation areas. 3) The partonic shock waves are centralitydependent ,pT-dependent and η-dependent. Outlook: 1) Special trigger particles and associated particles 2) System-size dependence including d+Au and p+p 3) Δη and ridge- correlations (17