Non-universal gauge bosons Z′ and lepton flavor-violating tau decays

Abstract

There are many models beyond the standard model predicting the existence of non-universal gauge bosons Z′, which can give rise to very rich phenomena. We calculate the contributions of the non-universal gauge bosons Z′, predicted by topcolor-assisted technicolor (TC2) models and flavor-universal TC2 models, to the lepton flavor-violating tau decays τ→liγ and τ→liljlk. We find that the branching ratio Br(τ→liljlk) is larger than that of the process τ→liγ in all of the parameter space. Over a sizable region of the parameter space, we have Br(τ→liljlk)∼10−8, which may be detected in the future experiments.