CP violating scalar Dark Matter

TL;DR

This paper explores a CP-violating extension of the inert doublet model, introducing new dark matter candidates and analyzing their relic density, while constraining the model with collider and detection experiment data.

Contribution

It presents a novel CP-violating inert doublet model with a mixed CP-charge dark matter candidate, expanding the viable parameter space compared to CP-conserving models.

Findings

New regions of dark matter relic density are identified due to CP-violation.

Parameter space is constrained using LHC and detection experiment data.

CP-violation allows for a mixed CP-charge dark matter candidate.

Abstract

We study an extension of the Standard Model (SM) in which two copies of the SM scalar $SU(2)$ doublet which do not acquire a Vacuum Expectation Value (VEV), and hence are \textit{inert}, are added to the scalar sector. We allow for CP-violation in the \textit{inert} sector, where the lightest \textit{inert} state is protected from decaying to SM particles through the conservation of a $Z_2$ symmetry. The lightest neutral particle from the \textit{inert} sector, which has a mixed CP-charge due to CP-violation, is hence a Dark Matter (DM) candidate. We discuss the new regions of DM relic density opened up by CP-violation, and compare our results to the CP-conserving limit and the Inert Doublet Model (IDM). We constrain the parameter space of the CP-violating model using recent results from the Large Hadron Collider (LHC) and DM direct and indirect detection experiments.