Dynamical quark-hadron phase transitions in heavy ion collisions

Abstract

In the expansion following an ultra-relativistic heavy ion collision, a dynamical phase transition of the matter from a quark-gluon plasma to a hadron gas can be accompanied by irreversible entropy production, as well as acceleration of the matter in passing through the transition. We show here, within the framework of a simple hydrodynamic model, that this entropy production is at most ∼7% of the initial entropy, and estimate the acceleration.