Comparison of results from a (2+1)-D relativistic viscous hydrodynamic model to elliptic and hexadecapole flow of charged hadrons measured in Au-Au collisions at sNN = 200 GeV

摘要

Simulated results from a (2+1)-D relativistic viscous hydrodynamic model have been compared to thenexperimental data on the centrality dependence of invariant yield, elliptic flow (v2), and hexadecapole flow (v4)nas a function of transverse momentum (pT ) of charged hadrons in Au-Au collisions atn√nsNN = 200 GeV. Resultsnfrom two types of initial transverse energy density profile, one based on the Glauber model and other based onnthe color glass condensate (CGC) model, are presented. We observe no difference in the simulated results onnthe invariant yield of charged hadrons for the calculations with different initial conditions. The comparison tonthe experimental data on invariant yield of charged hadrons supports a shear-viscosity to entropy-density ration(η/s) between 0 and 0.12 for the 0%–10% to 40%–50% collision centralities. The simulated v2(pT ) is found tonbe higher for a fluid with CGC based initial condition compared to Glauber based initial condition for a givenncollision centrality. Consequently the Glauber based calculations when compared to the experimental data requirena lower value of η/s relative to CGC based calculations. In addition, a centrality dependence of the estimatednη/s is observed from the v2(pT ) study. The v4(pT ) for the collision centralities 0%–10% to 40%–50% supports anη/s value between 0 and 0.08 for a CGC based initial condition. Simulated results using the Glauber based initialncondition for the ideal fluid evolution underestimate the v4(pT ) for collision centralities 0%–10% to 30%–40%.