Strongly First-Order Phase Transition in Real Singlet Scalar Dark Matter Model

TL;DR

This paper analyzes a simple extension of the standard model with a real singlet scalar, showing it can produce a strongly first-order electroweak phase transition and account for dark matter, but is excluded by current direct detection constraints.

Contribution

It provides analytical conditions for a strongly first-order electroweak phase transition in the real singlet scalar dark matter model and assesses its viability against experimental constraints.

Findings

Scalar can explain dark matter abundance before constraints

Model predicts a strongly first-order electroweak phase transition

Current direct detection experiments exclude the model

Abstract

The extension of the standard model by a real gauge singlet scalar is the simplest but the most studied model with sometimes controversial ideas on the ability of the model to address the dark matter and the electroweak phase transition issues simultaneously. For this model, we obtain analytically slightly different conditions for strongly first-order electroweak phase transition and apply that in computation of the dark matter relic density where the real scalar plays the role of the dark matter particle. We show that the scalar in this model before imposing the invisible Higgs decay constraint, can be responsible for all or part of the dark matter abundance, while at the same time gives rise to a strongly first-order electroweak phase transition required for the baryogenesis. When the constraints from the direct detection experiments such as XENON100 or LUX/XENON1t are considered, the model is excluded completely.