Initial eccentricity and constituent quark number scaling of elliptic flow in ideal and viscous dynamics

Abstract

In the Israel-Stewart's theory of dissipative hydrodynamics, we study the scaling properties elliptic flow in Au+Au collisions. Initial energy density of the fluid was fixed to reproduce STAR data on $\varphi$ meson multiplicity in 0-5% Au+Au collisions, such that irrespective of fluid viscosity, entropy at the freeze-out is similar in ideal or in viscous evolution. Initial eccentricity or constituent quark number scaling is only approximate in ideal or minimally viscous ($\eta /s=1/4\pi$) fluid. Eccentricity scaling become nearly exact in more viscous fluid ($\eta /s\ge$0.12). However, in more viscous fluid, constituent quark number scaled elliptic flow for mesons and baryons split into separate scaling functions. Simulated flows also do not exhibit 'universal scaling' i.e. elliptic flow scaled by the constituent quark number and charged particles $v_2$ is not a single function of transverse kinetic energy scaled by the quark number. From a study of violation of universal scaling, we obtain an estimate of QGP viscosity, $\eta /s=0.12\pm 0.03$.

Final version to be published in Phys. Rev. C. 8 pages, 10 figures.

References in corpus (15)

• Energy Loss and Flow of Heavy Quarks in Au+Au Collisions at sqrt(s_NN) = 200 GeV
• The QCD Equation of State with almost Physical Quark Masses
• Suppression of elliptic flow in a minimally viscous quark-gluon plasma
• Scaling properties of azimuthal anisotropy in Au+Au and Cu+Cu collisions at sqrt(s_NN) = 200 GeV
• Multiplicity scaling in ideal and viscous hydrodynamics
• Has the QCD Critical Point been Signaled by Observations at RHIC ?
• Centrality dependence of charged hadron and strange hadron elliptic flow from sqrt(s_NN) = 200 GeV Au+Au collisions
• The centrality dependence of elliptic flow, the hydrodynamic limit, and the viscosity of hot QCD
• Partonic flow and $\varphi$-meson production in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV
• Measuring Shear Viscosity Using Transverse Momentum Correlations in Relativistic Nuclear Collisions
• Dissipative effects from transport and viscous hydrodynamics
• Energy and system size dependence of charged particle elliptic flow and $v_2/\eps$ scaling
• Nearly perfect fluid in Au+Au collisions at RHIC
• Energy and system size dependence of elliptic flow: using rapidity gaps to suppress non-flow contribution
• PHENIX Studies of the Scaling Properties of Elliptic Flow at RHIC

Cited by in corpus (7)

• Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sqrt(s_NN) = 200 GeV
• Azimuthal anisotropies for Au+Au collisions in the parton-hadron transient energy range
• Large elliptic flow in low multiplicity pp collisions at LHC energy $\sqrt{s}$=14 TeV
• Knudsen number, ideal hydrodynamic limit for elliptic flow and QGP viscosity in $\sqrt{s}$=62 and 200 GeV Cu+Cu/Au+Au collisions
• Transverse momentum spectra and elliptic flow in ideal hydrodynamics and geometric scaling
• Hadronic resonance gas and charged particle's $p_T$ spectra and elliptic flow in $\sqrt{s}$=200 GeV Au+Au collisions
• Causal dissipative hydrodynamics for heavy ion collisions