Complementary collider and astrophysical probes of multi-component Dark Matter

TL;DR

This paper proposes a two-component Dark Matter model within a 3-Higgs Doublet Model framework, demonstrating how collider and astrophysical experiments can jointly probe the distinct properties of the two DM candidates.

Contribution

It introduces a novel 3HDM with a specific symmetry leading to two distinct DM particles, and explores their detectability through collider and astrophysical signals.

Findings

Light DM detectable via nuclear recoil in direct detection

Heavy DM observable through photon flux in indirect detection

Collider signatures include scalar cascade decays with two DM candidates

Abstract

We study a new physics scenario with two inert and one active scalar doublets, hence a 3-Higgs Doublet Model (3HDM). We impose a $Z_2 \times Z'_2$ symmetry onto such a 3HDM with one inert doublet odd under the $Z_2$ transformation and the other odd under the $Z'_2$ one. Such a construction leads to a two-component Dark Matter (DM) model. It has been shown that, when there is a sufficient mass difference between the two DM candidates, it is possible to probe the light DM candidate in the nuclear recoil energy in direct detection experiments and the heavy DM component in the photon flux in indirect detection experiments. With the DM masses at the electroweak scale, we show that, independently of astrophysical probes, this model feature can be tested at the Large Hadron Collider via scalar cascade decays in $2 \ell + \cancel{E}_T$ final states. We study several observable distributions whose shapes hint at the presence of the two different DM candidates.