Constraints on heavy decaying dark matter with current gamma-ray measurements

TL;DR

This paper uses current gamma-ray data from multiple observatories to set new limits on the lifetime of decaying dark matter across a wide mass range, highlighting the potential of gamma-ray and neutrino observations for dark matter searches.

Contribution

It provides the first comprehensive bounds on heavy decaying dark matter using the latest gamma-ray flux limits across a broad mass spectrum, including comparisons with future neutrino telescope projections.

Findings

Established new lower bounds on dark matter lifetime for masses between 10^7 and 10^15 GeV.

Identified decay channels with the most stringent constraints.

Compared gamma-ray constraints with future neutrino telescope sensitivities.

Abstract

Among the several strategies for indirect searches of dark matter, one very promising one is to look for the gamma-rays from decaying dark matter. Here we use the most up-to-date upper bounds on the gamma-ray flux from $10^5$ to $10^{11}$ GeV, obtained from CASA-MIA, KASCADE, KASCADE-Grande, Pierre Auger Observatory, and Telescope Array. We obtain global limits on dark matter lifetime in the range of masses $m_\mathrm{DM}=[10^7-10^{15}]~\mathrm{GeV}$. We provide the bounds for a set of decay channels chosen as representatives. The constraints derived here are new and cover a region of the parameter space not yet explored. We compare our results with the projected constraints from future neutrino telescopes, in order to quantify the improvement that will be obtained by the complementary high-energy neutrino searches.