Family gauge bosons with an inverted mass hierarchy

A model that gives family gauge bosons with an inverted mass hierarchy is proposed, stimulated by Sumino's cancellation mechanism for the QED radiative correction to the charged lepton masses. The Sumino mechanism cannot straightforwardly be applied to SUSY models because of the nonrenormalization theorem. In this Letter, an alternative model which is applicable to a SUSY model is proposed. It is essential that family gauge boson masses m(Aij) in this model is given by an inverted mass hierarchy m(Aii)∝1/√(mei), in contrast to m(Aii)∝√(mei) in the original Sumino model. Phenomenological meaning of the model is also investigated. In particular, we notice a deviation from the e-μ universality in the tau decays.