Influence of hydrodynamics on the interpretation of the high $p_T$ hadron suppression at RHIC

Abstract

A hybrid parameterization including contributions of hydrodynamics and of expectations from the spectral shape observed in p+p collisions is introduced. This parameterization can successfully describe identified hadron spectra over a wide range of $p_T$ in Au+Au reactions at $\sqrt{s_{NN}}$ = 200 GeV for all centralities. The parameters of the hydrodynamic source compare reasonably well to other attempts to describe the spectra. The description is obtained using one universal suppression factor of the hard scattering component independent of $p_T$ and hadron species. For the fit results obtained the observed nuclear modification factor for the different particles converges to a universal suppression behavior for $p_T>6\mathrm{GeV}/c$.

updated version (only typos), 16 pages, 10 figures