Asymmetric Inelastic Inert Doublet Dark Matter from Triplet Scalar Leptogenesis

TL;DR

This paper explores a model linking dark matter asymmetry with baryogenesis via leptogenesis, analyzing scalar and fermion doublet candidates, their relic abundance, and experimental constraints, highlighting viable dark matter candidates consistent with current data.

Contribution

It introduces a unified mechanism for dark matter and baryon asymmetry generation through scalar triplet decays, incorporating neutrino mass generation and experimental data analysis.

Findings

Scalar doublet DM of TeV mass is disfavored by Xenon100 data.

Fermion doublet DM around 100 GeV fits DAMA and Xenon100 constraints.

Model links dark matter asymmetry with leptogenesis and neutrino masses.

Abstract

The nature of dark matter (DM) particles and the mechanism that provides their measured relic abundance are currently unknown. In this paper we investigate inert scalar and vector like fermion doublet DM candidates with a charge asymmetry in the dark sector, which is generated by the same mechanism that provides the baryon asymmetry, namely baryogenesis-via-leptogenesis induced by decays of scalar triplets. At the same time the model gives rise to neutrino masses in the ballpark of oscillation experiments via type II seesaw. We discuss possible sources of depletion of asymmetry in the DM and visible sectors and solve the relevant Boltzmann equations for quasi-equilibrium decay of triplet scalars. A Monte-Carlo-Markov-Chain analysis is performed for the whole parameter space. The survival of the asymmetry in the dark sector leads to inelastic scattering off nuclei. We then apply bayesian statistic to infer the model parameters favoured by the current experimental data, in particular the DAMA annual modulation and Xenon100 exclusion limit. The latter strongly disfavours asymmetric scalar doublet DM of mass $\mathcal{O}(\TeV)$ as required by DM-$\bar{\rm DM}$ oscillations, while an asymmetric vector like fermion doublet DM with mass around 100 GeV is a good candidate for DAMA annual modulation yet satisfying the constraints from Xenon100 data.