Aspects of the cosmology of right-handed sneutrinos without lepton-number violation

In this work we add a Dirac right-handed neutrino superfield to the Minimal Supersymmetric Standard Model (MSSM). We discuss the interactions of the right- handed (RH) sneutrino and its mixing with its left-handed counterpart. We study the possibility of this RH sneutrino to be the lightest supersymmetrie particle (LSP). We obtain that this dark matter candidate is a non-thermal relic, and generally has a small relic density. This we argue makes it an interesting candidate for addressing the Ω(_DM)/ Ω(_b) problem. We then discuss a lepton-number conserving leptogenesis scenario, in which an Affleck-Dine inspired mechanism generates a left-right asymmetry in the sneutrino sector. The left-handed part of this asymmetry eventually genesis mechanism, as the right-handed part of the left-right asymmetry becomes the observed dark matter density.EThOS - Electronic Theses Online ServiceGBUnited Kingdo