EFFECTIVE MEAN-FIELD APPROXIMATION IN HOT FINITE SYSTEMS

An effective mean field approximation for finite systems at finite temperature which incorporates a multiplicity in the intrinsic partition function is derived in the context of the static path approximation. The approach exhibits a smooth behavior without sharp transitions. Moreover, the saddle point approximation around the new mean field is seen to provide an accurate estimate of the static path integral at all temperatures. Results are shown for a heavy nucleus with a quadrupole interaction.