Nucleation of Quark Matter in the PQM Model

We use Langer's theory to calculate the surface tension of critical bubbles in a first-order quark-hadron phase transition at moderate and high baryon chemical potential, as predicted by the Polyakov-Quark-Meson (PQM) model at the mean-field level. We define an effective 4-dimensional order parameter, which is used to overestimate the surface tension of nucleating bubbles within the thin-wall approximation. We find relatively low values for the surface tension, Sigma less than or similar to 15MeV/fm(2). This implies that a metastable state, such as a supercooled quark-gluon plasma (QGP), quickly decays even in regions relatively close to the coexistence line of the phase diagram. Possible consequences for cosmology are briefly outlined.