Mirror neutrons as dark matter in the Mirror Twin Two Higgs Doublet Model

TL;DR

This paper proposes a model where mirror neutrons serve as dark matter within the Mirror Twin Two Higgs Doublet framework, addressing previous issues with dark matter self-interactions and aligning with current experimental constraints.

Contribution

It introduces a two-Higgs-doublet extension that allows mirror neutrons to be the dominant dark matter component, improving cosmological viability with minimal tuning.

Findings

Mirror neutrons can constitute dark matter in the model.

Current collider, flavor, and cosmological constraints are compatible.

The model requires only slight tuning adjustments.

Abstract

In addition to being a solution to the little hierarchy problem, the Mirror Twin Higgs provides a natural setting for Asymmetric Dark Matter. In its incarnation with only one Higgs doublet and its mirror copy, dark matter would however almost certainly consist mostly of mirror atoms, which is severely ruled out by constraints on dark matter self-interactions. By adding a second Higgs doublet and its mirror, the vevs of the different Higgses can be arranged such that dark matter consists mostly of mirror neutrons, which is cosmologically viable. In this paper, it is shown that current constraints from colliders, flavour and cosmology can accommodate such a vev structure with little increase in the necessary tuning.