# Indirect Detection of Composite (Asymmetric) Dark Matter

## TL;DR

This paper explores how bound state formation and subsequent gamma-ray emissions from asymmetric dark matter can be used to detect and constrain dark matter properties through indirect astrophysical observations.

## Contribution

It introduces a novel indirect detection mechanism for asymmetric dark matter via bound state formation and gamma-ray signatures, considering different interaction scenarios.

## Key findings

- Strong signals for strongly-interacting dark matter due to bound state formation.
- Multiple photon lines for electroweak-charged dark matter in the TeV range.
- Diffuse spectra and CMB constraints for dark photon coupled dark matter below 1 TeV.

## Abstract

Dark Matter can form bound states upon the emission of quanta of energy equal to the binding energy. The rate of this process is large for strongly-interacting Dark Matter, and further enhanced by long distance effects. The resulting monochromatic and diffuse $\gamma$-rays can be tested in indirect detection experiments. If Dark Matter has electroweak charge, indirect signals include multiple observable photon lines for masses in the TeV range. Else if it couples only via a dark photon portal, diffuse spectra from dwarf galaxies and CMB reionization set powerful limits for masses below a TeV. This mechanism provides a powerful means of probing Asymmetric Dark Matter today.