The Isentropic Equilibrium Deconfining Phase Transition in the Extended Bag Model

Abstract

By using an Ansatz for the pressure (measured in terms of the bag constant) of the hadronic gas in equilibrium, we have formulated a new bag-type model for the phase transition, i. e. the extended bag model. This allows one to take into account the nonperturbative vacuum effects from both sides of the equilibrium condition. We have explicitly shown that our model automatically provides an isentropic equilibrium deconfining phase transition from the quark-gluon plasma phase to the hadronic gas phase with a temperature and chemical potential dependent bag pressure at the phase boundary. This makes it possible to regulate the total entropy and baryon number in both phases, i. e. the flow of the specific entropy per baryon across the phase boundary. We have also determined the functional form of the temperature and chemical potential dependence of the bag pressure outside the phase boundary.