Centrality dependence of multiplicity, transverse energy, and elliptic flow from hydrodynamics

The centrality dependence of the charged multiplicity, transverse energy, a nd elliptic flow coefficient is studied in a hydrodynamic model, using a va riety of different initializations which model the initial energy or entrop y production process as a hard or soft process, respectively. While the cha rged multiplicity depends strongly on the chosen initialization, the p(T)-i ntegrated elliptic flow for charged particles as a function of charged part icle multiplicity and the p(T)-differential elliptic flow for charged parti cles in minimum bias events turn out to be almost independent of the initia l energy density profile. (C) 2001 Elsevier Science B.V. All rights reserve d.