Boosted dark matter from semi-annihilations in the galactic center

TL;DR

This paper explores how semi-annihilations of dark matter in the galactic center produce boosted dark matter particles, which could be detected by current and future experiments, offering new insights into dark matter properties.

Contribution

It introduces the concept of semi-annihilation driven boosted dark matter flux and evaluates its detectability in direct detection and neutrino experiments for sub-GeV masses.

Findings

Current experiments can detect boosted dark matter with semi-annihilation cross-sections much lower than cosmic-ray boosted dark matter constraints.

Upcoming experiments like DARWIN and DUNE could probe scattering cross-sections down to 10^{-37} cm^2 for 30 MeV to 1 GeV dark matter.

Semi-annihilation processes can significantly enhance the detection prospects of light dark matter particles.

Abstract

In some scenarios, the dark matter relic abundance is set by the semi-annihilation of two dark matter particles into one dark matter particle and one Standard Model particle. These semi-annihilations might still be occurring today in the Galactic Center at a significant rate, generating a flux of boosted dark matter particles. We investigate the possible signals of this flux component in direct detection and neutrino experiments for sub-GeV dark matter masses. We show that for typical values of the semi-annihilation cross-section, the sensitivity of current experiments to the spin-independent dark matter-proton scattering cross-section can be several orders of magnitude larger than current constraints from cosmic-ray boosted dark matter. We also argue that the upcoming DARWIN and DUNE experiments may probe scattering cross-sections as low as $10^{-37}\,{\rm cm}^2$ for masses between 30 MeV and 1 GeV.