Synchrotron Self-Compton Process for Constraining sub-GeV Dark Matter in Omega Centauri via SKA

TL;DR

This paper proposes using synchrotron self-Compton emission from MeV-scale dark matter annihilation in Omega Centauri, observed with SKA, to set unprecedented constraints on dark matter properties in the sub-GeV mass range.

Contribution

It introduces a novel indirect detection method for sub-GeV dark matter using SSC emission, providing constraints that surpass existing limits even under conservative assumptions.

Findings

Constraints on annihilation cross section reach ~10^{-30} cm^3/s

Potential to improve limits below 10^{-32} cm^3/s

Outperforms existing indirect detection methods

Abstract

The search for the particle identity of dark matter (DM) continues to be a primary objective in modern physics. In this field, the sub-GeV mass range of DM detection remains a crucial yet challenging window. We investigate synchrotron self-Compton (SSC) emission from electrons and positrons produced by MeV-scale DM annihilation as a novel indirect detection channel. Focusing on the globular cluster Omega Centauri and the sensitivity of the Square Kilometre Array, we derive constraints on the annihilation cross section reaching $\langle\sigma v\rangle \sim 10^{-30}\,\rm{cm}^{3}\,\rm{s}^{-1}$ in the tens-of-MeV range. Furthermore, constraints could even reach below $\langle\sigma v\rangle \sim 10^{-32}\,\rm{cm}^{3}\,\rm{s}^{-1}$ for extreme parameter choices. Remarkably, even under deliberately conservative astrophysical assumptions, this channel outperforms existing indirect limits, establishing SSC emission as a robust probe of sub-GeV DM.