The Origin of Neutrino Masses and Physics Beyond the Standard Model

Abstract

We discuss the simplest models for the generation of neutrinos masses at tree level and one-loop level. The realization of the different seesaw mechanisms in the context of renormalizable SU(5) and SO(10) theories is reviewed. A new mechanism for the generation of neutrino masses at one-loop level is presented. We discuss the first realization of the Type III seesaw mechanism in the context of a renormalizable SU(5) theory, called "Adjoint SU(5)".