Duke University Chiho NONAKA in Collaboration with Masayuki Asakawa (Kyoto University) Hydrodynamical Evolution near the QCD Critical End Point June 26, McGill University, Montreal
C.NONAKA 06/26/ Critical End Point in QCD ? Critical End Point in QCD ? Z. Fodor and S. D. Katz ( JHEP 0203 (2002) 014 ) NJL model (Nf = 2) Lattice (with Reweighting) K. Yazaki and M.Asakawa., NPA 1989 Suggestions 2SC CFL T RHIC GSI Critical end point
C.NONAKA 06/26/ Phenomenological Consequence ? Phenomenological Consequence ? Divergence of Fluctuation Correlation Length critical end point M. Stephanov, K. Rajagopal, and E.Shuryak, PRL81 (1998) 4816 Still we need to study EOS Focusing Dynamics (Time Evolution) Hadronic Observables : NOT directly reflect properties at E Fluctuation, Collective Flow If expansion is adiabatic.
C.NONAKA 06/26/ How to Construct EOS with CEP? Assumption Critical behavior dominates in a large region near end point Near QCD end point singular part of EOS Mapping Matching with known QGP and Hadronic entropy density Thermodynamical quantities EOS with CEP r h T QGP Hadronic 3d Ising Model Same Universality Class QCD
C.NONAKA 06/26/ EOS of 3-d Ising Model Parametric Representation of EOS Guida and Zinn-Justin NPB486(97)626 h : external magnetic field QCD Mapping T r h
C.NONAKA 06/26/ Thermodynamical Quantities Singular Part of EOS near Critical Point Gibbs free energy Entropy density Matching Entropy density Thermodynamical quantities Baryon number density, pressure, energy density r h T QGP Hadronic
C.NONAKA 06/26/ Equation of State CEP Entropy Density Baryon number density
C.NONAKA 06/26/ Comparison with Bag + Excluded Volume EOS Comparison with Bag + Excluded Volume EOS With End Point Bag Model + Excluded Volume Approximation (No End Point) Focused Not Focused = Usual Hydro Calculation n /s trajectories in T- plane B
C.NONAKA 06/26/ Slowing out of Equilibrium Slowing out of Equilibrium B. Berdnikov and K. Rajagopal, Phys. Rev. D61 (2000) Berdnikov and Rajagopal’s Schematic Argument along r = const. line Correlation length longer than eq h faster (shorter) expansion r h slower (longer) expansion Effect of Focusing on ? Focusing Time evolution : Bjorken’s solution along n B /s fm, T 0 = 200 MeV eq
C.NONAKA 06/26/ Correlation Length (I) Widom’s scaling low eq depends on n /s. Max. Trajectories pass through the region where is large. (focusing) eq B r h
C.NONAKA 06/26/ Correlation Length (II) time evolution (1-d) Model C (Halperin RMP49(77)435) is larger than at Tf. Differences among s on n /s are small. In 3-d, the difference between and becomes large due to transverse expansion. eq B
C.NONAKA 06/26/ Consequences in Experiment (I) CERES: nucl-ex/ Fluctuations CERES 40,80,158 AGeV Pb+Au collisions No unusually large fluctuation CEP exists in near RHIC energy region ? Mean P T Fluctuation
C.NONAKA 06/26/ Consequences in Experiment (II) Xu and Kaneta, nucl-ex/ (QM2001) Kinetic Freeze-out Temperature J. Cleymans and K. Redlich, PRC, 1999 ? Low T comes from large flow. f ? Entropy density EOS with CEP EOS with CEP gives the natural explanation to the behavior of T. f
C.NONAKA 06/26/ CEP and Its Consequences Realistic hydro calculation with CEP Future task Slowing out of equilibrium Large fluctuation Freeze out temperature at RHIC Fluctuation Its Consequences Focusing
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C.NONAKA 06/26/ Hadronic Observables Fluctuations Mean transverse momentum fluctuation Charge fluctuations D-measure Dynamical charge fluctuation Balance function Collective Flow Effect of EOS Jeon and Koch PRL85(00)2076 Pruneau et al, Phys.Rev. C66 (02) Gazdzicki and Mrowczynski ZPC54(92)127 Korus and Mrowczynski, PRC64(01) Asakawa, Heinz and Muller PRL85(00)2072 Bass, Danielewicz, Pratt, PRL85(2000)2689 Rischke et al. nucl-th/
C.NONAKA 06/26/ Baryon Number Density Critical end point 1st order crossover Crossover : st order :
C.NONAKA 06/26/ n B /S contours S nBnB n B /S Focusing !
C.NONAKA 06/26/ Focusing and CEP
C.NONAKA 06/26/ FocusingFocusing What is the focusing criterion ? r h T h r CEP contours From our model Dominant terms Critical behavior etc.
C.NONAKA 06/26/ FocusingFocusing Scavenius et al. PRC64(2001) Analyses from Linear sigma model & NJL model They found the Critical point in T- plane. NJL model Sigma model The critical point does not serve as a “focusing” point ! Sigma model NJL model n B /S lines in plane
C.NONAKA 06/26/ Hydrodynamical evolution Au+Au 150AGeV b=3 fm
C.NONAKA 06/26/ Relativistic Hydrodynamical Model Relativistic Hydrodynamical Equation Baryon Number Density Conservation Equation Lagrangian hydrodynamics Space-time evolution of volume element Effect of EoS Flux of fluid
C.NONAKA 06/26/ Sound Velocity Clear difference between n /s=0.01 and 0.03 B Effect on Time Evolution Collective flow EOS Sound velocity along n /s B /L TOTAL /L TOTAL