Complex Scalar Dark Matter in G2HDM

TL;DR

This paper investigates the properties and constraints of complex scalar dark matter within the G2HDM framework, analyzing its viability under current experimental limits and exploring future detection prospects.

Contribution

It provides a detailed analysis of the parameter space for complex scalar DM in G2HDM, considering multiple experimental constraints and identifying viable compositions.

Findings

Inert doublet scalar dominated DM is excluded by current constraints.

Remaining DM compositions can be tested by future gamma-ray observations.

The model remains consistent with collider and precision measurements.

Abstract

The complex scalar dark matter (DM) candidate in the gauged two Higgs doublet model (G2HDM), stabilized by a peculiar hidden parity ($h$-parity), is studied in detail. We explore the parameter space for the DM candidate by taking into account the most recent DM constraints from various experiments, in particular, the PLANCK relic density measurement and the current DM direct detection limit from XENON1T. We separate our analysis in three possible compositions for the mixing of the complex scalar. We first constrain our parameter space with the vacuum stability and perturbative unitarity conditions for the scalar potential, LHC Higgs measurements, plus Drell-Yan and electroweak precision test constraints on the gauge sector. We find that DM dominated by composition of the inert doublet scalar is completely excluded by further combining the previous constraints with both the latest results from PLANCK and XENON1T. We also demonstrate that the remaining parameter space with two other DM compositions can be further tested by indirect detection like the future CTA gamma-ray telescope.