Lepton Flavor Violation in Complex SUSY Seesaw Models with Nearly Tribimaximal Mixing

TL;DR

This paper investigates lepton flavor violation in complex SUSY seesaw models with nearly tribimaximal mixing, analyzing how CP phases influence branching ratios and their correlation with mixing parameters.

Contribution

It provides a comprehensive survey of lepton flavor violation branching ratios in complex SUSY seesaw models with nearly tribimaximal mixing, including CP-violating effects and phase dependencies.

Findings

Branching ratios can be enhanced by 2-3 orders of magnitude with CP violation.

Strong dependence of LFV rates on CP phases affects their correlation with mixing parameters.

LFV rates are largely uncorrelated with high- and low-energy lepton mixing parameters.

Abstract

We survey the lepton flavor violation branching ratios Br(mu->e,gamma), Br(tau->mu,gamma), and Br(tau->e,gamma) in mSUGRA for a broad class of lepton mass matrix textures that give nearly tribimaximal lepton mixing. Small neutrino masses are generated by the type-I seesaw mechanism with non-degenerate right-handed neutrino masses. The textures exhibit a hierarchical mass pattern and can be understood from flavor models giving rise to large leptonic mixing. We study the branching ratios for the most general CP-violating forms of the textures. It is demonstrated that the branching ratios can be enhanced by 2-3 orders of magnitude as compared to the CP-conserving case. The branching ratios exhibit, however, a strong dependence on the choice of the phases in the Lagrangian which affects the significance of flavor models. In particular, for general CP-phases, the lepton flavor violating rates appear to be essentially uncorrelated with the possible high- and low-energy lepton mixing parameters, such as the reactor angle.