Lepton Flavor Violating Decays as Probes of Neutrino Mass Spectra and Heavy Majorana Neutrino Masses

Abstract

We investigate the lepton flavor violating (LFV) rare decays in the supersymmetric minimal seesaw model in which the Frampton-Glashow-Yanagida ansatz is incorporated. The branching ratio of $\mu \to e\gamma$ is calculated in terms of the Snowmass Points and Slopes (SPS). We find that the inverted mass hierarchy is disfavored by all SPS points. In addition, once the ratio of BR$(\tau \to \mu \gamma )$ to BR$(\mu \to e\gamma )$ is measured, one may distinguish the normal and inverted neutrino mass hierarchies, and confirm the masses of heavy right-handed Majorana neutrinos by means of the LFV processes and the thermal leptogenesis mechanism. It is worthwhile to stress that this conclusion is independent of the supersymmetric parameters.

Comments: 12 pages, 5 figures, 1 table. Comments and references added, accepted for publication in Phys. Rev. D