See-Saw Induced CMSSM Lepton-Flavour Violation Post-WMAP

Abstract

The see-saw mechanism of neutrino mass generation, when incorporated in supersymmetric theories with supergravity mediated supersymmetry breaking, results in low-energy lepton-flavour violation arising from the soft supersymmetry breaking slepton masses. The parameter space of supergravity theories with conserved R-parity is severely constrained by the requirement that the LSP provide cold dark matter with a relic density in the range indicated by the recent WMAP measurements, as well as by laboratory constraints. We calculate the $\meg$ branching ratio for the constrained minimal supersymmetric standard model, over the range of parameters consistent with WMAP and laboratory constraints, in families of see-saw model parameterizations which fit the low energy neutrino measurements. We find that over much of the range of see-saw models, for supersymmetry parameters consistent with WMAP and laboratory bounds, the resulting predicted rates for $\meg$ (and other charged lepton flavour violating processes) are within current experimental limits, but that these rates should be detectable with the next generation of lepton-flavour violation experiments.