# Exceptional Composite Dark Matter

## TL;DR

This paper explores a composite Higgs model with an $SO(7)$ symmetry breaking to $G_2$, proposing a stable dark matter candidate arising from pseudo-Nambu-Goldstone bosons, with phenomenology determined by the compositeness scale.

## Contribution

It introduces a novel composite dark matter candidate within an $SO(7)$ to $G_2$ symmetry breaking framework, analyzing its stability and relic abundance.

## Key findings

- Dark matter can be an electroweak triplet or singlet within the model.
- Relic density and signals depend on the compositeness scale $f$.
- Dark matter mass is around a few TeV, consistent with experimental bounds.

## Abstract

We study the dark matter phenomenology of non-minimal composite Higgs models with $SO(7)$ broken to the exceptional group $G_2$. In addition to the Higgs, three pseudo-Nambu-Goldstone bosons arise, one of which is electrically neutral. A parity symmetry is enough to ensure this resonance is stable. In fact, if the breaking of the Goldstone symmetry is driven by the fermion sector, this $\mathbb{Z}_2$ symmetry is automatically unbroken in the electroweak phase. In this case, the relic density, as well as the expected indirect, direct and collider signals are then uniquely determined by the value of the compositeness scale, $f$. Current experimental bounds allow to account for a large fraction of the dark matter of the Universe if the dark matter particle is part of an electroweak triplet. The totality of the relic abundance can be accommodated if instead this particle is a composite singlet. In both cases, the scale $f$ and the dark matter mass are of the order of a few TeV.