Lepton flavor violation in minimal flavor violation extensions of the seesaw

Abstract

A minimal flavour violation hypothesis for leptons can be implemented essentially in two ways that are compatible with a type-I seesaw structure with three heavy singlet neutrinos $N$, and that satisfy the requirement of being predictive, in the sense that all lepton flavor violating (LFV) effects can be expressed in terms of low energy observables. The first realization is CP conserving and is based on the flavor group $SU(3{)}_e\times SU(3{)}_{\ell }\times O(3{)}_N$ (being $e$ and $\ell$ the SU(2) singlet and doublet leptons). The second realization allows for CP violation and is based on $SU(3{)}_e\times SU(3{)}_{\ell +N}$. I review the main features of the two schemes and point out their different implications for LFV observables.

Comments: 5 pages. Invited talk at the Workshop on e+ e- Collisions from \Phi\ to \Psi\ (PHIPSI08)}, September 19-22, 2011, Novosibirsk, Russia