Neutral and Millicharged Dark Matter Decay into Gamma-Ray Lines

TL;DR

This paper compares neutral and millicharged dark matter decay scenarios as potential sources of gamma-ray lines, using effective field theory and cosmic ray constraints to evaluate their viability.

Contribution

It provides a comparative analysis of neutral versus millicharged dark matter decay models for gamma-ray line signals, incorporating effective field theory and cosmic ray data.

Findings

Neutral and millicharged dark matter can produce gamma-ray lines under certain conditions.

Cosmic ray continuum constraints limit the parameter space for these decay scenarios.

The comparison highlights differences in detectability and theoretical plausibility.

Abstract

A gamma-ray line observation would be a strong hint towards the detection of dark matter. The possibility that a decay of the dark matter particle is responsible for the emission of a line is investigated, for both a neutral and a millicharged dark matter. We focus here on a comparison of these two scenarios, based on an effective field theory description and relying on cosmic ray continuum constraints.