Fizika | Áramlástan » Tetsufumi Hirano - Conference Summary, from a Hydrodynamic Point of View

Relativistic Relativistic Aspects Aspects of of Nuclear Nuclear Physics Physics Rio Riode deJaneiro, Janeiro,Brazil Brazil 33-6, -6, November, November,2008 2008 Conference Summary --From a Hydrodynamic Point of View-- Tetsufumi Hirano Department of Physics The University of Tokyo Japan Disclaimers To summarize in ~40 minutes • Not all talks. Beyond my ability! • (Mainly) from a theoretical point of view • (Mainly) topics on heavy ion physics • (Mainly) from a hydrodynamic point of view • I admit my talk I am going to give is highly biased. If you don’t find your name/study, forgive me! The Nobel Prize in 2008 went to Prof.Nambu! Photo taken at INPC2007, Tokyo Goals of H.IC • Properties of QCD matter under equilibrium (EoS, transport coefficients, etc.) • Confinement-Deconfinement mechanism • How chiral symmetry is dynamically broken (From Nambu-Goldstone phase to Wigner phase ) Lesson from Observational Cosmology “Best” cosmological parameters

C.LBennett et al,ApJSuppl(’03) Observation COBE, WMAP, CMB CMB tools: tools: CMBFAST, CMBFAST, CAMB, CAMB, Taken from http://lambda.gsfcnasagov/ Analysis codes play a major role in precision physics. “Observational QGP Physics” • Observational cosmology has been established through collaboration between theory and experiment communities. phenomenology people experimental people lattice people https://wiki.bnlgov/ TECHQM/ • Development of analysis codes is desperately needed to constrain QGP parameters. Hydrodynamics as the Heart of H.IC Initial condition (thermalization) Hydrodynamic evolution of QGP Information inside QGP •Jet quenching/Di-jet •Heavy quark diffusion •J/psi suppression •Electromagnetic radiation • Recombination Coalescence Information on surface of QGP Kinetic evolution Hadronic spectra (Collective flow) Hydrodynamics as a Starting Point of Finite T/μB QCD in H.IC • Reminder: Hydrodynamics is based on an ansatz of local

thermal equilibrium. • There is no a priori reason why hydrodynamics would be applicable in nuclear collisions. • Suppose hydrodynamics did not work at all in H.IC, one could not say anything about phase of QCD, finite temperature/density physics, and so on in the context of H.IC Summary Slide by TH @ Quark Matter 2004 Need Sophisticated Models Pratt HYDRODYNAMICAL MODELING OF HEAVY ION COLLISIONS hadron gas time Cutting-Edge Dynamical Modeling Based on Ideal Hydro QGP fluid Hadron phase: 1. Hadronic fluid(chemically frozen) 2. Hadronic cascade (UrQMD, RQMD, JAM) 3. Continuous particle emission, HKM QGP fluid: Ideal hydrodynamics (1D, 2D, or 3D) Initial condition: 1. Glauber 2. Color Glass Condensate 3. NeXus, EPOS, UrQMD, 4. Flux tube collision axis Pratt, Sinyukov, Werner, Petersen, 0 Au Au Takahashi, Csernai, Grassi, Nonaka, See also, Bass, Dumitru (2000) Teaney,Lauret,Shuryak(2001) Hirano et al.(2006) Bumpy vs. Smooth IC Csernai Petersen

Event-by-Event Hydro Simulation Energy density in an event from NeXus Grassi Sizable effect on elliptic flow Solid: Event average Dashed: Smooth I.C See also, Gyulassy, Rischke, Zhang (1997) Effect of Eccentricity Fluctuation on v2 v2(w.rot) ~ 2 v2(worot) at Npart~350 in AuAu v2(w.rot) ~ 4 v2(worot) at Npart~110 in CuCu Significant effects of fluctuation! Hirano Hadronic Rescattering Effects EPOS+3D ideal hydro+UrQMD: Mass ordering of v2 can be attributed to hadronic rescattering. See also, T.Hirano et al(2008) Werner Pion Emission Distribution Hydro-Kinetic Approach Sinyukov Ideal hydro (blink): Kolb & Heinz(2003) Hydro+Cascade: Hirano Pion Emission Distribution Hydro-Kinetic Approach Sinyukov Ideal hydro (blink): Kolb & Heinz(2003) Hydro+Cascade: Hirano VISCOSITY Necessity of Relaxation Time Non-relativistic case (Cattaneo(1948)) Balance eq.: Constitutive eq.: Fourier’s law τ : “relaxation time” Parabolic equation (heat equation)

ACAUSAL! Finite τ Hyperbolic equation (telegraph equation) “Full I-S Eq.” is not Full 2nd Order Eq. Gradient expansion (lambda/L) Rischke Numerical Simulation of Viscous Fluids “Simplified” I-S equations Chaudhuri Effect of Bulk Viscosity on Freezeout See also, Denicol et al. (P11); 0805.1719;08073120;08083170 Mechanism to work hydro+cascade? Torrieri Hydrodynamic Limit? 0.35 Au-Au, Gl. Cu-Cu, Gl. Au-Au, CGC (/2) Cu-Cu, CGC (/2) 0.3 hydro v2 /εGl. v2/ε 0.25 0.2 0.15 vhydro /εCGC (/2) 2 0.1 0.05 0 0 0.2 0.4 0.6 0.8 1 -1 (1/S) (dN/dy) [mb ] 1.2 1.4 Hydrodynamic limit at LHC? What happens if hydro+cascade results are fitted? Ollitrault, Snelling, Xu Relevant Scale in Coupling pQCD(+renormalization) ~lattice QCD!? RHIC ~ LHC Peshier How Do Partons Get Longitudinal Momentum to Thermalize? Free Streaming etas=y Sheet: etas=const dN/dy dN/dy Width Æ “Thermal” fluctuation Sum of delta functions y=eta y≈etas

Modeling Pre-Thermalization Stage Strickland Glasma Flux Tube and Ridge Before a collision: Random and transverse color E and B fields (Color Glass Condensate) Just after a collision: Longitudinal color E and B fields Decay of longitudinal fields Æ Correlation McLerran Imaging Flux Tubes Three pillars (RIDGE): Flux tubes + thermalization + radial flow Congrats! Takahashi, Grassi Trivial before Non-Trivial: Energy-Momentum Conservation-Induced Constrains (EMCICs) Lisa (Possible) Application of Hydro Results Thermal Jet quenching Recombination J/psi suppression Coalescence Heavy quark diffusion radiation (photon/dilepton) Meson J/psi c Baryon c bar Information along a path Information on surface Information inside medium Open Hydro Data http://karman.physicspurdueedu/ OSCAR/ http://tkynt2.physsu-tokyoacjp/ ~hirano/parevo/parevo.html Hard Probes Global Fit Using Hydro Data Salgado (Possible) Application of Hydro Results Thermal Jet

quenching Recombination J/psi suppression Coalescence Heavy quark diffusion radiation (photon/dilepton) Meson J/psi c Baryon c bar Information along a path Information on surface Information inside medium HEAVY FLAVOR Profs.Kobayashi and Maskawa http://www.nagoya-uacjp/info/news/news081007html J/psi suppressed or not at LHC? c c Color Screening Braun-Munzinger Heavy Quark Evolution in QGP background Aichelin RHIC and LHC as Factories of Exotics Diquark correlation is a key to understand sQGP Ko (Possible) Application of Hydro Results Thermal Jet quenching Recombination J/psi suppression Coalescence Heavy quark diffusion radiation (photon/dilepton) Meson J/psi c Baryon c bar Information along a path Information on surface Information inside medium Penetrating Probes Sinha Di-Lepton Spectra at LHC Sensitivity to isotropic time scale Strickland FUTURE PROSPECTS LHC Data, Coming Soon! Snelling, Takai Beam Energy Scan at

RHIC Odyniec, Xu Hallman “Bxxx” Phase Diagram just conjectured diagram Where is it, IF EXIST? •Experiment +phenomelogy •Lattice Bauer, Lombardo, Scoccola, Nonaka, Is There a Critical Point? “3D Columbia Plot” Lombardo Another scenario (existence of C.P) is possible How to Observe? pbar/p ratio has a non-trivial behavior as a function of pT. Nonaka Let’s thank Takeshi Kodama, Eduardo Fraga and local organizers for excellent organization of the conference. Key: Large Angle Emission of Gluons in Transport ggÅÆgg Pang,Zhang,Gyulassy,Molnar This does not help the system to thermalize. gg ÅÆ ggg Xu, Greiner, Greiner (absent) Not just a higher order! One can interpret early thermalization, large v2, and jet quenching