Phases of chiral gauge theories - art. no. 125009

We discuss the behavior of two non-supersymmetric chiral SU(N) gauge theori es, involving fermions in the symmetric and antisymmetric two-index tensor representations respectively. In addition to global anomaly matching, we em ploy a recently proposed inequality constraint on the number of effective l ow energy (massless) degrees of freedom of a theory, based on the thermodyn amic free energy. Several possible zero temperature phases are consistent w ith the constraints. A simple picture for the phase structure emerges if th ese theories choose the phase, consistent with global anomaly matching, tha t minimizes the massless degree of freedom count defined through the free e nergy. This idea suggests that confinement with the preservation of the glo bal symmetries through the formation of massless composite fermions is in g eneral not preferred. While our discussion is restricted mainly to bilinear condensate formation, higher dimensional condensates are considered for on e case. We conclude by commenting briefly on two related supersymmetric chi ral theories.