Phenomenology of supersymmetric neutrino mass models

Abstract

The origin of neutrino masses is currently one of the most intriguing questions of particle physics and many extensions of the Standard Model have been proposed in that direction. This experimental evidence is a very robust indication of new physics, but is not the only reason to go beyond the Standard Model. The existence of some theoretical issues supports the idea of a wider framework, supersymmetry being the most popular one. In this thesis, several supersymmetric neutrino mass models have been studied. In the first part, the phenomenology of models with bilinear-like R-parity violation is discussed in great detail, highlighting the most distinctive signatures at colliders and low energy experiments. In particular, the correlations between the LSP decay and neutrino physics are shown to be a powerful tool to put this family of models under experimental test. Other important signatures are investigated as well, like majoron emission in charged lepton decays for the case of models with spontaneous breaking of R-parity. A very different approach is followed in the second part of the thesis. Supersymmetric models with a Left-Right symmetry have all the ingredients to incorporate a type-I seesaw mechanism for neutrino masses and conserve R-parity at low energies. In this case, which only allows for indirect tests, the generation of neutrino masses at the high seesaw scale is encoded at low energies in the slepton soft masses. Contrary to minimal seesaw models, sizeable flavor violation in the right slepton sector is expected. Its experimental observation would be a clear hint of an underlying Left-Right symmetry, providing valuable information about physics at very high energies.