FROM CRITICALITY TO SUPERCOOLING IN EXPANDING HOT NUCLEAR-MATTER - POSSIBLE EXPLANATION OF LOW-TAU PUZZLE

A model of an expanding hot nuclear matter is discussed. A Fokker-Plan ck equation is used to describe the conversion of the gaseous phase in to the liquid phase. It is shown that the apparent exponent tau(eff) e ntering the power-law fit to charge fragment distribution sigma(Z)prop ortional to Z(-tau eff) differs considerably from the critical exponen t tau. If the nuclear matter is strongly supercooled, tau(eff) should be small both for small and for large systems. This fact may serve as a possible explanation of the low values of tau(eff), obtained recentl y at Michigan State University.