Indirect Detection of Sub-GeV Dark Matter Coupling to Quarks

TL;DR

This paper explores how low-mass dark matter particles interacting with quarks could produce detectable photon signals, using chiral perturbation theory to predict spectral features, and evaluates upcoming experiments' sensitivity to these signals.

Contribution

It introduces a method to predict photon signals from sub-GeV dark matter annihilation or decay into hadronic states using chiral perturbation theory, and assesses future experimental sensitivities.

Findings

Spectral features in photon signals from sub-GeV dark matter are identified.

Upcoming experiments like e-ASTROGAM and AMEGO could detect these signals.

Branching fractions to hadronic states can be reliably estimated with chiral perturbation theory.

Abstract

We consider photon signals arising from the annihilation or decay of low-mass (sub-GeV) dark matter which couples dominantly to quarks. In this scenario, the branching fractions to the various kinematically accessible hadronic final states can largely be determined from chiral perturbation theory. Several of these final states yield striking spectral features in the sub-GeV photon spectrum. New experiments, such as e-ASTROGAM and AMEGO, are in development to improve sensitivity in this energy range, and we discuss their potential sensitivity to this class of models.