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

The centrality dependence of the charged multiplicity, transverse energy, and elliptic flow coefficient is studied in a hydrodynamic model, using a variety of different initializations which model the initial energy or entropy production process as a hard or soft process, respectively. While the charged multiplicity depends strongly on the chosen initialization, the p(T)-integrated elliptic flow for charged particles as a function of charged particle multiplicity and the p(T)-differential elliptic flow for charged particles in minimum bias events turn out to be almost independent of the initial energy density profile. (C) 2001 Elsevier Science B.V. All rights reserved.