Sneutrino dark matter and the observed anomalies in cosmic rays

摘要

We revisit sneutrino dark matter in light of the recent results from the PAMELA and ATIC experiments.In the U(1)B-L extension of the minimal supersymmetric standard model the right-handed sneutrinois a natural candidate for thermal dark matter. Sneutrino annihilation at the present time can beconsiderably 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 charges. A sneutrino mass inthe 1–2 TeV range provides a good fit to the PAMELA data and a reasonable fit to the ATIC data. Withinthis mass range the sneutrino–nucleon elastic scattering cross section is 10-11–10-9 pb, which mightbe probed by upcoming and future direct detection experiments. In addition, if (at least) one of theneutrinos is dominantly a Dirac fermion, the sneutrino can provide a unified picture of dark matter andinflation.