Lepton flavor violation and seesaw symmetries

When the standard model is extended with right-handed neutrinos the symmetries of the resulting Lagrangian are enlarged with a new global U(1)R Abelian factor. In the context of minimal seesaw models we analyze the implications of a slightly broken U(1)R symmetry on charged lepton avor violating decays. We nd, depending on the R-charge assignments, models where charged lepton avor violating rates can be within measurable ranges. In particular, we show that in the resulting models due to the structure of the light neutrino mass matrix muon avor violating decays are entirely determined by neutrino data (up to a normalization factor) and can be sizable in a wide right-handed neutrino mass range. Keywords Neutrino mass and mixings Right handed neutrinos Decays of lepton