Prospects for the detection of dark matter with long-lived mediators in the Sun using the Southern Wide-field Gamma-ray Observatory

Abstract

The operation of the next generation of gamma-ray observatories will lead to a great advance in dark matter searches. In this paper, we use the hidden sectors hypothesis within the so-called secluded models to calculate the capabilities of the Southern Wide-field Gamma-ray Observatory (SWGO) to detect gamma-ray signatures produced by dark matter particles concentrated in the Sun. We assume the dark matter particle annihilates into metastable mediators which decay into γγ, e+e-, τ+τ-, and b̅b outside the Sun. We found that the SWGO will be able to probe a spin-dependent cross-section of about 10-46 cm2 for dark matter masses smaller than 5 TeV. This result shows an unprecedented sensitivity surpassing the current instruments by more than one order of magnitude.