Dark matter asymmetry in supersymmetric Dirac leptogenesis

TL;DR

This paper explores various dark matter candidates within supersymmetric Dirac leptogenesis, proposing mechanisms to evade overabundance issues and detailing how different particles can serve as viable dark matter.

Contribution

It introduces a singlet superfield coupling to right-handed neutrinos, enabling multiple dark matter candidates and addressing overabundance problems in supersymmetric Dirac leptogenesis.

Findings

Singlino can be a naturally asymmetric dark matter candidate.

Right-handed sneutrino can serve as a symmetric dark matter candidate via thermal freeze-out.

Non-thermal production of dark matter from late-decaying particles is consistent with big-bang nucleosynthesis.

Abstract

We discuss asymmetric or symmetric dark matter candidate in the supersymmetric Dirac leptogenesis scenario. By introducing a singlet superfield coupling to right-handed neutrinos, the overabundance problem of dark matter can be evaded and various possibilities for dark matter candidate arise. If the singlino is the lightest supersymmetric particle (LSP), it becomes naturally asymmetric dark matter. On the other hand, the right-handed sneutrino is a symmetric dark matter candidate whose relic density can be determined by the usual thermal freeze-out process. The conventional neutralino or gravitino LSP can be also a dark matter candidate as its non-thermal production from the right-handed sneutrino can be controlled appropriately. In our scenario, the late-decay of heavy supersymmetric particles mainly produce the right-handed sneutrino and neutrino which is harmless to the standard prediction of the big-bang nucleosynthesis.