Indirect Searches for Dark Photon-Photon Tridents in Celestial Objects

Abstract

We model and constrain the unique indirect detection signature produced by dark matter particles that annihilate through a $U(1)$ gauge symmetry into dark photons that subsequently decay into three-photon final states. We focus on scenarios where the dark photon is long-lived, and show that ${\hat{I}}^3$-ray probes of celestial objects can set strong constraints on the dark matter/baryon scattering cross section that in many cases surpass the power of current direct detection constraints, and in some cases even peer into the neutrino fog.

12 pages, 7 figures (8 sub-figures), 3 tables