Systematic parameter study of hadron spectra and elliptic flow from viscous hydrodynamic simulations of Au+Au collisions at sqrt(s_NN) = 200 GeV

摘要

Using the (2+1)-dimensional viscous hydrodynamic code VISH2+1, we presentsystematic studies of the dependence of pion and proton transverse momentumspectra and their elliptic flow in 200 A GeV Au+Au collisions on the parametersof the hydrodynamic model (thermalization time, initial entropy densitydistribution, decoupling temperature, equation of state, and specific shearviscosity eta/s). We identify a tension between the slope of the protonspectra, which (within hydrodynamic simulations that assume a constant shearviscosity to entropy density ratio) prefer larger eta/s values, and the slopeof the p_T-dependence of charged hadron elliptic flow, which prefers smallervalues of eta/s. Changing other model parameters does not appear to permitdissolution of this tension