Two-loop effective potential, thermal resummation and first-order phase transitions: Beyond the high-temperature expansion

摘要

We study a finite temperature two-loop resummed effective potential in theAbelian gauge theory. A tractable calculation scheme without using ahigh-temperature expansion is devised. We apply it to the Abelian-Higgs modeland its extension to a minimal supersymmetric standard model-like model andstudy the thermal phase transition. It is shown that our scheme improves theprevious results about 10% in the quantities relevant to the phase transition,and its impacts on bubble dynamics could be even more sizable. It still holdsthat the stop-stop-gluon sunset diagram enhances the strength of thefirst-order phase transition even without the high-temperature expansion.