Inert dark matter in three Higgs doublet model: a blind spot narrative

TL;DR

This paper investigates a three Higgs doublet model with an inert doublet and a $ ext{Z}_3 imes ext{Z}_2$ symmetry, revealing a blind spot in dark matter detection where scattering cross-sections vanish.

Contribution

It introduces a novel (2+I)HDM-$ ext{Z}_3$ model with a detailed phenomenological analysis including vacuum stability, relic abundance, and direct detection constraints.

Findings

Identification of a blind spot in dark matter direct detection.

Constraints on model parameters from vacuum stability and unitarity.

Parameter space consistent with relic abundance and detection limits.

Abstract

We explore the phenomenology of three Higgs doublet scenario, where the scalar potential is augmented by $\mathbb{Z}_{3} \times \mathbb{Z}_{2}$ symmetry making one doublet inert. Thus in effect, our model of interest is two Higgs plus inert Higgs doublet model charged under $\mathbb{Z}_3$ ((2+I)HDM-$\mathbb{Z}_3$) symmetry. We observe a blind spot feature for dark matter direct detection, as the tree-level dark matter-nucleon scattering cross-section vanishes depending on the mass splitting of dark sector particles. We perform a detailed analysis based on vacuum stability, unitarity, relic abundance, and direct detection results on the model. We also perform profile likelihood analysis and constrain the corresponding parameter space.