Dark matter and neutrino masses in the R-parity violating NMSSM

Abstract

The R-parity symmetry-violating (RPV) version of the next-to-minimal supersymmetric standard model (NMSSM) is attractive simultaneously with regard to the so-called μ-problem and the accommodation of three-flavor neutrino data at tree level. In this context, we show here that if the lightest supersymmetric particle (LSP) is the gravitino, it possesses a lifetime larger than the age of the universe since its RPV-induced decay channels are suppressed by the weak gravitational strength. This conclusion holds if one considers gravitino masses ∼102 GeV as in supergravity scenarios and is robust if the lightest pseudoscalar Higgs field is as light as ∼10 GeV (as may occur in the NMSSM). For these models, predicting in particular an RPV neutrino–photino mixing, the gravitino lifetime exceeds the age of the universe by two orders of magnitude. However, we find that the gravitino cannot constitute a viable dark matter candidate since its too large RPV decay widths would then conflict with the flux data of last indirect detection experiments. The cases of a sneutrino LSP or a neutralino LSP as well as the more promising gauge-mediated supersymmetry-breaking scenario are also discussed. Both the one-flavor simplification hypothesis and the realistic scenario of three neutrino flavors are analyzed. We have modified the NMHDECAY program to extend the neutralino mass matrix to the present framework.