Direct Detection of Mirror Matter in Twin Higgs Models

TL;DR

This paper investigates the potential for direct detection experiments to identify mirror baryons and electrons in Twin Higgs models, considering their sub-nano-charged nature and various galactic distributions, to uncover the mirror dark matter's properties.

Contribution

It introduces a framework for detecting sub-nano-charged mirror particles in direct detection experiments, analyzing different galactic distributions and their impact on detection prospects.

Findings

Mirror dark matter could be detected via nuclear and electron recoil experiments.

Different galactic distributions (halo or disk) affect detection rates.

Recoil energy analysis can reveal mirror particle masses and charges.

Abstract

We explore the possibility of discovering the mirror baryons and electrons of the Mirror Twin Higgs model in direct detection experiments, in a scenario in which these particles constitute a subcomponent of the observed DM. We consider a framework in which the mirror fermions are sub-nano-charged, as a consequence of kinetic mixing between the photon and its mirror counterpart. We consider both nuclear recoil and electron recoil experiments. The event rates depend on the fraction of mirror DM that is ionized, and also on its distribution in the galaxy. Since mirror DM is dissipative, at the location of the Earth it may be in the form of a halo or may have collapsed into a disk, depending on the cooling rate. For a given mirror DM abundance we determine the expected event rates in direct detection experiments for the limiting cases of an ionized halo, an ionized disk, an atomic halo and an atomic disk. We find that by taking advantage of the complementarity of the different experiments, it may be possible to establish not just the multi-component nature of mirror dark matter, but also its distribution in the galaxy. In addition, a study of the recoil energies may be able to determine the masses and charges of the constituents of the mirror sector. By showing that the mass and charge of mirror helium are integer multiples of those of mirror hydrogen, these experiments have the potential to distinguish the mirror nature of the theory. We also carefully consider mirror plasma screening effects, showing that the capture of mirror dark matter particles in the Earth has at most a modest effect on direct detection signals.