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Dynamical Modeling and Soft Physics at RHIC and the LHC. Huichao Song . Peking University . NFQCD2013, Kyoto, Japan, Nov.18-Dec.20,2013. Selected Topics : (1) QGP viscosity at RHIC and the LHC (2) Initial State fluctuations & final state correlations
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Dynamical Modeling and Soft Physics at RHIC and the LHC Huichao Song Peking University NFQCD2013, Kyoto, Japan, Nov.18-Dec.20,2013 Selected Topics: (1) QGP viscosity at RHIC and the LHC (2) Initial State fluctuations & final state correlations (3) Elliptic flow for strange & multi-strange hadrons (4) Soft particle yields and Chemical Freeze-out at the LHC (5) Dynamical modeling near the critical point 12/04/2013
Viscous Hydrodynamics viscous hydrodynamics Song & Heinz PLB08, PRC08 Neglect bulk viscosity Assume zero net baryon density & heat conductivity at RHIC and LHC 2+1-d: OSU, INT, Stony Brook, Pudue, Calcutta (2008), Crakow, Frankfurt(2010) 3+1-d: Mcgill(2011), MSU(2012), Crakow(2012), Nagoya(2013)
Viscous Hydro + hadron Cascade Hybrid Model ideal hydro (QGP & HRG) viscous hydro(QGP & HRG) Initial conditions viscous hydro hadron cascade viscous hydro (QGP) + URQMD (HRG) QGP HRG HRG H. Song, S. Bass, U. Heinz, PRC2011
Event-by-event hydrodynamics Single shot simulations: smoothed initial conditions (before 2010) E-b-E simulations: fluctuating initial conditions (since 2010) B. Schenke et al, Phys.Rev. C85 (2012) 024901
(1)Extracting QGP viscosity from elliptic flow data – VISHNU results
VISHNU hybrid model & QGP viscosity (2011) H. Song, S. Bass, U. Heinz, T. Hirano, and C. Shen, PRL2011 MC-KLN MC-Glauber -Main uncertainties come from initial conditions -Other uncertainties (much smaller) -Initial flow, bulk viscosity, single shot vs. e-b-e calculations (each of them shift V2 by a few percent, partial cancellation among them)
V2 and QGP viscosity at the LHC Song, Bass & Heinz, PRC 2011 The average QGP viscosity is slightly larger at the LHC Please also refer to C. Gale, et al., ArXiv: 1209.5330 [nucl-th]
LHC: spectra for identified hadrons H. Song, S. Bass, U. Heinz, arXiv:13110157 [nucl-th] -a nice fit for pions, kaons and proton spectra
LHC: for identified hadrons VISHNU H. Song, S. Bass, U. Heinz, arXiv:13110157 [nucl-th] A very nice fit of V2(PT) for all centrality bins at LHC from VISHNU hybrid model
(2) Initial State Fluctuations, Final State Correlations & the QGP viscosity
Uncertainties from Initial Conditions H. Song, S. Bass, U. Heinz, T. Hirano, and C. Shen, PRL2011 MC-KLN MC-Glauber Main uncertainties come from initial conditions MC-KLN, larger HIGHER value of QGP viscosity MC-Glauber, smaller LOWER value of QGP viscosity
MC-KLN & MC-Glauber initializations & V3 Pure viscous hydro simulations : Qiu, Shen & Heinz, PLB2012 V3 prefer lower value of QGP viscosity
Initialization & Pre-equilibrium: Updates after 2011 -fluctuations of nucleon positions: MC-Glauber, MC-KLN -fluctuations of color charges (in the framework of CGC): IP-Glasma:B. Schenke et al., arXiv:1202.6646; 1206.6805 [nucl-th] -Pre-equilibriums: Correlated Fluctuation:B. Muller & A. Schafer, arXiv:1111.3347 [hep-ph] . URQMD initialization:H.Petersen & M. Bleicher, Phys. Rev. C81, 044906,2010 AMPT initialization: L. Pang, Q.Wang & X.Wang, arXiv:1205.5019[nucl-th] EPOS/NEXUS initialization:K. Werner et al., Phys. Rev. C83:044915,2011 -fluctuations of local gluon numbers (in the famework of MC-KLN): Multiplicity fluctuations:A. Dumitru and Y. Nara, Phys. Rev. C 85, (2012) 034907 … … … … Mostly, the effects of initializations /pre-equilibrium dynamics was studied with ideal hydro. Their quantitative influences on are still unknown.
Flow at RHIC & LHC: results from IP-Glasma + MUSIC Gale, Jeon ,Schenke, Tribedy &Venugopalan PRL2013
New Observables for Higher Order Flow Harmonics Luzum & Ollitrault, 2012-10 Qiu & Heinz,12-08 C. Gale et al. 12-09 -A further study of flow data in different aspects, using e-b-e hybrid model -They are all sensitive to the QGP viscosity will constrain initialization models, tightening the limit on
Massive data evaluating • Early CHIMERA Results (Comprehensive Heavy Ion Model Evaluation and Reporting Algorithm) Spectra spectra elliptic flow HBT R. Soltz, et al., arXiv:1208.0897[nucl-th] -- Massive data evaluating algorithm becoming available
QGP viscosity at RHIC and the LHC (1) H. Song, NPA2013 (3) (2) (5) (4) (1) Luzum& Romatschke, PRC 2008 RHIC (2) Song, Bass, Heinz, Hirano, and Shen, PRL2011, PRC2011 (3) Song, Bass, Heinz, PRC2011 LHC (4) Qiu, Shen & Heinz, PLB 2012 (5) Gale, Jeon ,Schenke, Tribedy & Venugopalan, PRL2013
(3) Soft Particle Yields & Chemical Freeze-out Temperature at the LHC Tch= 164MeV v.s. Tch= 150MeV J. Stachel,SQM 2013
dN/dyfor identified hadrons (RHIC & LHC) H. Song, S. Bass, U. Heinz, arXiv:1311.0157 [nucl-th] RHIC : 200 A GeVAu+Au LHC : 2.76 A TeVPb+Pb -VISHNU nicely describes the multiplicity for pions, kaons & protons VISHNU: Tsw= 165MeV
dN/dyfor identified hadrons (RHIC & LHC) H. Song, S. Bass, U. Heinz, arXiv:13110157 [nucl-th] RHIC : 200 A GeVAu+Au LHC : 2.76 A TeVPb+Pb -VISHNU nicely describes the multiplicity for pions, kaons & protons -B-Bbar annihilations plays an important role for a nice fit of the proton data VISHNU : Tsw= 165MeV Please also refer to F. Becattini et al., PRC2012
dN/dyfor identified hadrons (RHIC & LHC) J. Stachel,SQM 2013 LHC : 2.76 A TeVPb+Pb -B-Bbar annihilations plays an important role for a nice fit of the proton data Statistical Model : Tch~ 150 MeV (no B-Bbar annihilations!) A system with B-Bbar annihilations does not reach chemical freeze-out ! VISHNU : Tsw= 165MeV
(4) Elliptic flow for Strange & multi-strange hadrons
v2 of Strange & Multi-strange Hadrons Song et al., arXiv:1310.3462 [nucl-th] -Nice descriptions of Lambda, Xi and Omega V2 at various centralities
UrQMD freeze-out time distributions Song et al., in preparation Preliminary Omega pions proton Lambda Xi -On Average Lamba freeze-out even later than pion and protons! -earlier freeze-out for Xi and Omega!
VISHNU vs Hydro with Tdec=165 & 100 MeV Song et al., in preparation Preliminary -freeze-out temperature for Lambda is much below Tc! -freeze-out temperatures for Omega and xi are closer to Tc!
Elliptic flow for phi at the LHC Song, Bass & Heinz, arXiv:1311. 0157 200A GeV Au+Au -Hadron cascade: small cross sections for phi -mass ordering between phi and proton are independent of collision energies, centralities & theoretical details T. Hirano 3+1-d ideal hydro+JAM
Elliptic flow for phi at the LHC Song, Bass & Heinz, arXiv:1311. 0157 200A GeV Au+Au T. Hirano 3+1-d ideal hydro+JAM 200A GeV Au+Au
phi V2 in strong & weakly coupling limit H. Song, S. Bass, U. Heinz, arXiv:13110157 [nucl-th] -hydro + Tdec =165 MeV weakly coupling limit -hydro + Tdec =100 MeV strong coupling limit VISHNU: small cross sections for phi Neither the strongly nor the weakly coupling limit nor the cases in between (VISHNU) could explain the mass-ordering between proton & phi shown by STAR phi-meson puzzle !
(6) Beyond Hydrodynamics dynamical modeling near the critical point Critical Fluctuations: At critical point : Size effects: It is important to address the effects from dynamical evolutions
Dynamical modeling near the critical point -mean field approximation quark & anti-quark is treated as the heat bath (fluid), which interact with the chiral field via effective mass order parameter K. Peach, H. Stocker and A. Dumitru, PRC2003
propagation of initial fluctuations -mean field approximation fluid g=5.5 fluid g=3.7 Critical point First -order K. Peach, H. Stocker and A. Dumitru, PRC2003
Dynamical modeling near the critical point -beyond mean field M.Nahrgang, S.leupold. C. Herold, M. Bleicher , PRC 2011 : damping : noise, Jiang &Song preliminary
Dynamical modeling near the critical point (Chiralfluid dynamics with a Polyakov loop PNJL) C. Herold, et, al. PRC 2012 First -order Critical point -To compare with the experimental data, systematic treatment of freeze-out with external field is necessary
Summary (1) QGP viscosity at RHIC and the LHC -(MC-Glauber; MC-KLN) -Approximately similar averaged QGP viscosity at RHIC and LHC energies (2) Initial state fluctuations & final state correlations -New observables to constrain QGP viscosity & initial conditions (3) Soft particle yields & chemical freeze-out at the LHC -B-Bbar annihilation plays an important role for proton yields -Effective chemical freeze-out of the system with B-Bbar annihilation (4) Elliptic flow for strange & multi-strange hadrons -phi-elliptic flow needs a better understanding (5) Dynamical modeling near the critical point -External sigma field re-organize the structure of initial & internal fluctuations -systematic treatment of the freeze-out with external field is needed in the future