Sneutrino dark matter in light of PAMELA

Abstract

In the U(1)_{B-L} extension of the minimal supersymmetric standard model the right-handed sneutrino is a natural candidate for thermal dark matter. Sneutrino annihilation at the present time can be considerably enhanced due to the exchange of the lightest field in the Higgs sector that breaks U(1)_{B-L}. The annihilation mainly produces taus (or muons) by the virtue of B-L charge assignments. A sneutrino mass of 1-2 TeV provides a good fit to the PAMELA and is compatible with the latest results from the FERMI experiment. In addition, the sneutrino-nucleon elastic scattering cross section is within the reach of the upcoming and future direct detection experiments.