Gravitino Dark Matter, Neutrino Masses and Lepton Flavor Violation from broken R-parity

Abstract

We study gravitino dark matter and slow gravitino decays in supersymmetric theories with broken R‐parity. It turns out that for the model parameters that may give rise to viable radiative neutrino masses, and visible R‐violating signatures in colliders, gravitinos are cosmologically stable and can be good dark matter candidates. On the contrary, the decays of the Next‐to‐Lightest Supersymmetric Particle are fast, and can be easily reconciled with Big Bang Nucleosynthesis. For the interesting range of parameters, observable lepton flavour violation is also to be expected, with rates that are strongly dependent from the flavour structure of the R‐violating operators, and with distinct correlations that should be distinguishable in the coming generation of experiments.