Dark matter in the Georgi-Machacek model with an additional inert doublet

TL;DR

This paper investigates an extended Georgi-Machacek model with an inert doublet, identifying a viable dark matter candidate and analyzing its relic abundance, detection prospects, and collider constraints.

Contribution

It introduces an inert doublet to the Georgi-Machacek model, providing a natural dark matter candidate and exploring its phenomenological viability.

Findings

Collider constraints do not exclude the model.

Most parameter points are ruled out by direct detection.

A viable dark matter candidate exists at 250 GeV mass.

Abstract

We study a model that extends the Georgi-Machacek model by the addition of an inert doublet, $\Phi_2$. This allows for the model to contain a natural dark matter candidate, $H^0$. For a number of benchmark points at two DM candidate masses ($m_{H^0} \in \{70,\,250\}$ GeV), we determine the relic abundance, direct detection cross section, and collider constraints. We find that the collider studies used do not constrain the model. For the parameter region chosen, the points are ruled out by direct detection experimental results. At the lower mass point, we do not find a viable parameter point, while at the higher mass we do find an additional point that satisfies all the applied constraints.