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Explore quark matter, phase transitions & heavy ion collisions, key findings on deconfinement, superfluidity & QCD critical point. Discussion on QGP signals in STAR collaboration & puzzles in heavy ion collisions.
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Recent Progress in the Study onQuark Matter and Its Realization in Heavy Ion Collisions 庄鹏飞 (清华大学)高能物理大会,南昌2010
QCD Phase Transitions and Relativistic Heavy Ion Collisions FAIRU+U@Elab = 40A GeV RHICAu+Au@√s = 200A GeV deconfinement, chiral symmetry restoration, color superconductivity, pion superfluidity, …… STAR合作组中国成员: 清华大学 中国科技大学 华中师范大学 山东大学 上海应用物理所 兰州近代物理所 LHCPb+Pb@√s = 5.5A TeV CSRU+U@Elab = 0.6A GeV
pair dissociation line sQGP BCS BEC Strongly Coupled Quark Matter lattice 2009: more non-perturbative when charm quark is thermalized, 50% contribution ! Point:the validity of a weak coupling expansion depends not only on the strength of the coupling, but also on the number of active degrees of freedom ! Conclusion: two possible sQGP states: a) independent quasi-partons b) partons + bound states
QCD at High Density ● BCS-BEC crossover in QCD ● lattice 2009: searching for the QCD critical point in canonical ensemble T QCD ● cold atoms nB ● does the quarkyonic matter exist in real world with Nc=3 and what is the measurable consequence of the quarkyonic matter ? He and Zhuang, PRD2007,2008,2009 ● D.Son: no deconfinement in isospin matter due to pion superfluidity, even at extremely high isospin density 王群,等 PRD2008 QCD at high temperature and density:刘玉鑫,宗红石,陈继胜,彭光雄,… ● Fridel oscillation at high density
AdS/CFT Correspondence weak coupling in gravity theory corresponds to strong coupling in gauge theory Bulk viscosity Kovtun, Son, Starinets, PRL94, (2005)111601: 黄梅,等 PRD2008,2009 pQCD lattice AdS/CFT Conclusion:minimal and maximum at the critical point, a possible way to pinpoint the location of a QCD phase transition 重夸克介子的熔解温度 侯德富,等 JHEP2008, 2009 Problems:CFT is not QCD, the coupling constant in AdS/CFT does not run, … 6
Signals of QGP Produced in Heavy Ion Collisions Jet quenching:(王恩科,…)喷注在热密物质中损失能量 Collective flow:(马余刚,刘峰,…) 体系的膨胀会产生集体流strong fluctuations:(吴元芳,…) 在QCD临界点附近 J/ψ Suppression:(唐泽波,许晓明,…)热密物质中有Debye屏蔽Electromagnetic Signals: (周代翠,…)电磁信号是最干净的信号Strangeness enhancement: (杨纯斌,陈列文,…)QGP中奇异夸克成对产生Local Parity Violation: 高温高密时对称性自发破缺
Signals from RHIC • STAR Jet quenching NCQ-scaling Large v2 • models Large radial flow Jet quenching a matter at parton level at RHIC !
Local Parity Violation Lee and Wick (PRD1973,1974):spontaneous P and T violation at high temperatureKharzeev (PRL1998, PLB2006):P-odd bubbles in deconfined QCD vacuum with Θ-term possible realization in non-central heavy ion collisions:
3 Puzzles in Heavy Ion Collisions (QM2009) 2)HBT Puzzle 1)DLS Puzzle low-mass dilepton enhancement, partial chiral restoration? A challenge for CSR! fireballs at SPS and RHIC have almost the same size ! E=1 A GeV 3) J/Psi puzzle: RAA (|y|<0.35) > RAA (1.2<|y|<2.2) RAA (RHIC, |y|<0.35) ≈ RAA (SPS)
J/Psi Production at RHIC and LHC Liu, Yan, Xu, Zhuang, PRL2006, PLB2009 J/Ψ suppression in hot matter (Matsui and Satz, 1986) Our approach: J/Ψ transport equation with QCD gluon dissociation + relativistic hydrodynamic equations + QCD equation of state 12
Partonic Wind at RHIC and LHC Zhu, Xu, Zhuang, PLB2007, PRL2008 angular correlation is a sensitive probe of sQGP: NN collisions: back-to-back correlation RHIC: almost no correlation LHC: near-side correlation c quark motion in QGP: we take drag coefficient as a parameter charactering the coupling strength QGP evolution: ideal hydrodynamics 13
Outlook 实验 SPS: 达到了产生QGP的条件 RHIC: 发现了产生QGP的一些信号 LHC: Properties of QGPFAIR,NICA,RHIC energy scan: QCD critical point CSR: Chiral symmetry restoration 理论 非微扰强相互作用多体问题难度很大 QCD at high density Strongly coupled quark matter Sensitive QGP signatures RHIC AdS/CFT Early Universe Compact Stars QGP 谢谢 ! BCS-BEC Lattice 14