Asymmetric Mediator in Scotogenic Model

TL;DR

This paper extends the scotogenic model by adding a Z_2 odd singlet scalar, creating a unified framework that links baryon asymmetry and dark matter density through asymmetric mediator decays, while also explaining neutrino properties.

Contribution

The paper introduces an extended scotogenic model with an asymmetric mediator that simultaneously generates lepton and dark matter asymmetries, connecting them to neutrino masses.

Findings

Predicts comparable baryon and dark matter energy densities

Provides a mechanism for asymmetric dark matter production

Explains neutrino masses and mixing angles

Abstract

The scotogenic model is the Standard Model (SM) with Z_2 symmetry and the addition of Z_2 odd right-handed Majorana neutrinos and SU(2)_L doublet scalar fields. We have extended the original scotogenic model by an additional Z_2 odd singlet scalar field that plays a role in dark matter. In our model, the asymmetries of the lepton and Z_2 odd doublet scalar are simultaneously produced through CP-violating right-handed neutrino decays. While the former is converted into baryon asymmetry through the sphaleron process, the latter is relaid to the DM density through the decay of SU(2)_L doublet scalar that is named "asymmetric mediator". In this way, we provide an extended scotogenic model that predicts the energy densities of baryon and dark matter being in the same order of magnitude, and also explains the low-energy neutrino masses and mixing angles.