Z(N) interface tension in a hot SU(N) gauge theory

Abstract The interface tension between Z( N ) vacua in a hot SU( N ) gauge theory (without dynamical fermions) is computed at next to leading order in weak coupling. The Z( N ) interface tension is related to the instanton of an effective action, which includes both classical and quantum terms; a general technique for treating consistently the saddle points of such effective actions is developed. Loop integrals which arise in the calculation are evaluated by means of zeta-function techniques. As a byproduct, up to two-loop order we find that the stable vacuum is always equivalent to the trivial one, and so respects charge-conjugation symmetry.