Massive neutrinos and μ → e, γ

Abstract

If neutrino masses and mixings are suitable to explain the atmospheric and solar neutrino fluxes, this amounts to contribution to FCNC processes, in particular μ → e, γ. We show that in the particularly interesting scenario of the supersymmetric see-saw, the prediction for BR(μ → e, γ) is in general larger than the experimental upper bound, unless the leptonic Yukawa matrices satisfy very precise (fine-tuned) requirements. This result has important implications for model building.