RESUMMATION AND THE MSW EFFECT INSIDE A SUPERNOVA CORE

The electron-neutrino (upsilon(e)) charged-current self-energy, in an ultra-degenerate medium of ultra-relativistic electrons, is examined i n the real-time approach of Thermal Field Theory. The starting point a re the hard thermal loop resummation techniques developed by Braaten a nd Pisarski and others. In such a way, an order alpha correction to th e standard MSW potential is found. In addition, the absence of electro n-mass singularities at O(alpha) is confirmed in a coherent process. ( C) 1997 Elsevier Science B.V.