A study of collider signatures for two Higgs doublet models with a Pseudoscalar mediator to Dark Matter

TL;DR

This paper investigates how existing LHC data constrains two Higgs doublet models with a pseudoscalar mediator to dark matter, exploring new parameter regions and their collider signatures.

Contribution

It provides the first constraints on unstudied scenarios of two Higgs doublet models with a pseudoscalar mediator using LHC measurements.

Findings

Certain parameter regions are already constrained by existing LHC data.

Relaxing assumptions broadens the range of detectable signatures.

New constraints are established on previously unexamined model scenarios.

Abstract

Two Higgs doublet models with an additional pseudoscalar particle coupling to the Standard Model and to a new stable, neutral particle, provide an attractive and fairly minimal route to solving the problem of Dark Matter. They have been the subject of several searches at the LHC. We study the impact of existing LHC measurements on such models, first in the benchmark regions addressed by searches and then after relaxing some of their assumptions and broadening the parameter ranges considered. In each case we study how the new parameters change the potentially visible signatures at the LHC, and identify which of these signatures should already have had a significant impact on existing measurements. This allows us to set some first constraints on a number of so far unstudied scenarios.