Right-handed sneutrino as thermal dark matter

Abstract

We study an extension of the minimal supersymmetric standard model with a singlet supermultiplet $S$ with coupling $S{H}_{1}{H}_{2}$ in order to solve the $\ensuremath{\mu}$ problem as in the next-to-minimal supersymmetric standard model, and right-handed neutrino supermultiplets $N$ with couplings $SNN$ in order to generate dynamically electroweak-scale Majorana masses. We show how in this model a purely right-handed sneutrino can be a viable candidate for cold dark matter in the Universe. Through the direct coupling to the singlet, the sneutrino cannot only be thermal relic dark matter but also have a large enough scattering cross section with nuclei to detect it directly in the near future, in contrast with most other right-handed sneutrino dark matter models.