Shrihari Gopalakrishna, André de Gouvêa, Werner Porod
Right-handed Sneutrinos as Nonthermal Dark Matter
Preprint series: ESI preprints

MSC:

81T60 Supersymmetric field theories

81V05 Strong interaction, including quantum chromodynamics

83E99 None of the above but in this section

PACS: 95.35.+d,14.80.Ly
Abstract: When the minimal supersymmetric standard model is augmented by three right-handed neutrino superfields, one generically predicts that the neutrinos acquire Majorana masses. We po
stulate that all supersymmetry (SUSY) breaking masses as well as the Majorana masses of the right-handed neutrinos are around the electroweak scale and, motivated by the smallness of neutrino masses, assume
that the lightest supersymmetric particle (LSP) is an almost-pure right-handed sneutrino.
We discuss the conditions under which this LSP is a successful dark matter candidate. In
general, such an LSP has to be nonthermal in order not to overclose the universe, and we
find the conditions under which this is indeed the case by comparing the Hubble expansion rate with the rates of the relevant thermalizing processes, including self-annihilation
and co-annihilation with other SUSY and standard model particles.

Keywords: Supersymmetry, Nonthermal Dark Matter