Scalar assisted singlet doublet fermion dark matter model and electroweak vacuum stability

TL;DR

This paper introduces an extended singlet doublet fermion dark matter model with a scalar field that improves electroweak vacuum stability and impacts dark matter properties, providing new insights into dark matter and vacuum stability.

Contribution

The paper proposes a novel extension of the singlet doublet dark matter model by adding a singlet scalar, which stabilizes the electroweak vacuum and influences dark matter phenomenology.

Findings

The scalar extension stabilizes the electroweak vacuum up to the Planck scale.

The scalar portal coupling affects dark matter relic density and detection limits.

Scalar mixing angle is significantly constrained by combined dark matter and vacuum stability analysis.

Abstract

We extend the so-called singlet doublet dark matter model, where the dark matter is an admixture of a Standard Model singlet and a pair of electroweak doublet fermions, by a singlet scalar field. The new portal coupling of it with the dark sector not only contributes to the dark matter phenomenology (involving relic density and direct detection limits), but also becomes important for generation of dark matter mass through its vacuum expectation value. While the presence of dark sector fermions affects the stability of the electroweak vacuum adversely, we find this additional singlet is capable of making the electroweak vacuum absolutely stable upto the Planck scale. A combined study of dark matter phenomenology and Higgs vacuum stability issue reflects that the scalar sector mixing angle can be significantly constrained in this scenario.