# Composite Twin Dark Matter

## TL;DR

This paper explores a specific Twin Higgs model where heavy twin bottom quarks form dark matter candidates as twin baryons or atoms, with potential for near-future detection and resolving astrophysical tensions.

## Contribution

It introduces a regime where twin bottom quarks are heavy, allowing precise calculations of bound states and proposing novel dark matter candidates in twin baryons or atoms.

## Key findings

- Dark matter can be composed of twin baryons or atoms in this model.
- Significant parameter space is compatible with current constraints and detectable soon.
- Twin atoms may resolve discrepancies in dark matter observations across astrophysical scales.

## Abstract

We consider Fraternal Twin Higgs models where the twin bottom quark, $b'$, is much heavier than the twin confinement scale. In this limit aspects of quark bound states, like the mass and binding energy, can be accurately calculated. We show that in this regime, dark matter can be primarily made of twin baryons containing $b' b' b'$ or, when twin hypercharge is gauged, twin atoms, composed of a baryon bound to a twin $\tau'$ lepton. We find that there are significant regions of parameter space which are allowed by current constraints but within the realm of detection in the near future. The case with twin atoms can alleviate the tension between dark matter properties inferred from dwarf galaxies and clusters.