In an ideal hydrodynamic model, with an equation of state where the confinement-deconfinement transition is a crossover at $T_{\mathit{co}}=196$ MeV, we have simulated $\sqrt{s}=200$ GeV Au$+$Au collisions. Simultaneous description of the experimental charged particle’s $p_T$ spectra and elliptic flow require that in central (0–$10\%$) Au$+$Au collisions, initial energy density scales with the binary collision number density. In less central collisions, experimental data demand scaling with the participant density. Simulation studies also indicate that in central collisions viscous effects are minimal.

• Received 31 March 2010

DOI:https://doi.org/10.1103/PhysRevC.81.067901