REHEATING AFTER SUPERCOOLING IN THE CHIRAL PHASE-TRANSITION

We study the conversion of the latent heat of a supercooled quark-gluon plasma into excitations of the pion field. Supercooling is predicted to occur in the late stages of the evolution of a quark-gluon plasma produced in energetic heavy-ion collisions, if the QCD phase transition is of first order. The supercooled, chirally symmetric state, which contains potential energy associated with an energetically unfavorable field configuration, eventually rolls down to the true minimum of the effective chiral potential. When this motion is described in terms of the linear sigma-model, we find that the energy of the coherent sigma-field is very efficiently converted into pionic excitations due to anharmonic oscillations around the minimum. The system is expected to partially thermalize before its disintegration.