RHIC multiplicity distributions and superposition models

Abstract

The recent PHENIX mid-rapidity measurements of multiplicity distributions for centrality bins are analyzed in the framework of superposition models. A simple superposition of pp events is shown to disagree with the heavy ion data for dispersion as a function of centrality. However, it is suggested that a model describing properly the pp data and based in the "wounded quark" idea may be compatible with the multiplicity data for heavy ion collisions.