Symmetry Non-restoration at High Temperature

Abstract

We discuss the (non)-restoration of global and local symmetries at high temperature. First, we analyze a two-scalar model with $Z_2 \times Z_2$ symmetry using the exact renormalization group. We conclude that inverse symmetry breaking is possible in this kind of models within the perturbative regime. Regarding local symmetries, we consider the $SU(2) \otimes U(1)$ gauge symmetry and focus on the case of a strongly interacting scalar sector. Employing a model-independent chiral Lagrangian we find indications of symmetry restoration.

8 pages, LaTex with sprocl.sty, 1 figure. To appear in the Proceedings of the International Workshop ``Beyond the Standard Model: from Theory to Experiment''