Dark Matter with Two Inert Doublets plus One Higgs Doublet

TL;DR

This paper explores a new inert doublet model with two inert doublets and one Higgs doublet, offering a richer dark matter phenomenology and potential for experimental constraints from LHC and direct detection data.

Contribution

It introduces the I(2+1)HDM with two inert doublets, expanding the dark matter model landscape and analyzing its phenomenology and experimental constraints.

Findings

New dark matter relic density regions identified.

Potential to constrain the model with LHC and direct detection data.

Richer phenomenology compared to previous inert doublet models.

Abstract

Following the discovery of a Higgs boson, there has been renewed interest in the general 2-Higgs-Doublet Model (2HDM). A model with One Inert Doublet plus One Higgs Doublet (I(1+1)HDM), where one of the scalar doublets is "inert" (since it has no vacuum expectation value and does not couple to fermions) has an advantage over the 2HDM since it provides a good Dark Matter (DM) candidate, namely the lightest inert scalar. Motivated by the existence of three fermion families, here we consider a model with two scalar doublets plus one Higgs doublet (I(2+1)HDM), where the two scalar doublets are inert. The I(2+1)HDM has a richer phenomenology than either the I(1+1)HDM or the 2HDM. We discuss the new regions of DM relic density in the I(2+1)HDM with simplified couplings and address the possibility of constraining the model using recent results from the Large Hadron Collider (LHC) and DM direct detection experiments.