  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.
