Scalar Neutrino as Asymmetric Dark Matter: Radiative Neutrino Mass and Leptogenesis

TL;DR

This paper proposes a model extending the MSSM with scalar triplets to revive the scalar neutrino as a viable asymmetric dark matter candidate, linking neutrino masses and baryon asymmetry via leptogenesis.

Contribution

It introduces a mass splitting mechanism for scalar neutrinos in an extended MSSM, enabling them to serve as dark matter and connect neutrino mass generation with leptogenesis.

Findings

Scalar neutrino can be a dark matter candidate with mass splitting.

Radiative Majorana neutrino masses are generated.

Dark matter abundance is related to baryon asymmetry through leptogenesis.

Abstract

In the Minimal Supersymmetric Standard Model (MSSM), the scalar neutrino $\tilde{\nu}_L$ has odd R parity, yet it has long been eliminated as a dark-matter candidate because it scatters elastically off nuclei through the $Z$ boson, yielding a cross section many orders of magnitude above the experimental limit. We show how it can be reinstated as a dark-matter candidate by splitting the masses of its real and imaginary parts in an extension of the MSSM with scalar triplets. As a result, radiative Majorana neutrino masses are also generated. In addition, decays of the scalar triplets relate the abundance of this asymmetric dark matter to the baryon asymmetry of the Universe through leptogenesis.