TRANSITION FROM A QUARK-GLUON PLASMA IN THE PRESENCE OF A SHARP FRONT

The effect of a sharp front separating the quark-gluon plasma phase fr om the hadronic phase is investigated. Energy-momentum conservation an d baryon number conservation constrain the possible temperature jump a cross the front. If one assumes that the temperature in the hadronic p hase is T congruent-to 200 MeV, as has been suggested by numerous resu lts from relativistic ion collisions, one can determine the correspond ing temperature in the quark phase with the help of continuity equatio ns across the front. The calculations reveal that the quark phase must be in a strongly supercooled state. The stability of this solution wi th respect to minor modifications is investigated. In particular the e ffect of an admixture of hadronic matter in the quark phase (e.g. in t he form of bubbles) is considered in detail. In the absence of admixtu re the transition proceeds via a detonation transition and is accompan ied by a substantial super-cooling of the quark-gluon plasma phase. Th e detonation is accompanied by less supercooling if a small fraction o f bubbles is allowed. By increasing the fraction of bubbles the superc ooling becomes weaker and eventually the transition proceeds via a smo other deflagration wave.