Dark Matter as the Trigger of Strong Electroweak Phase Transition

TL;DR

This paper explores how scalar dark matter candidates can trigger a strong first-order electroweak phase transition, linking dark matter properties with baryogenesis and Higgs phenomenology.

Contribution

It systematically analyzes scalar dark matter models, identifying the doublet as the simplest candidate that can induce a strong electroweak phase transition.

Findings

Dark matter mass between 45 and 80 GeV.

Lower bound on direct detection rate.

Higgs decay width constraints.

Abstract

In this Letter, we propose a new possible connection between dark matter relic density and baryon asymmetry of the universe. The portal between standard model sector and dark matter not only controls the relic density and detections of dark matter, but also allows the dark matter to trigger the first order electroweak phase transition. We discuss systematically possible scalar dark matter candidates, starting from a real singlet to arbitrary high representations. We show that the simplest realization is provided by a doublet, and that strong first-order electroweak phase transition implies a lower bound on the dark matter direct detection rate. The mass of dark matter lies between 45 and 80 GeV, allowing for an appreciable invisible decay width of the Standard Model Higgs boson, which is constrained to be lighter than 130 GeV for the sake of the strong phase transition.