Dark Astronomy with Dark Matter Detectors

TL;DR

This paper proposes a new method called dark astronomy to detect dark radiation emitted by dissipative dark sectors, using underground experiments and resonant conversion techniques to map dark radiation sources in our galaxy.

Contribution

It introduces a novel detection mechanism based on dark-photon-to-photon conversion, enhancing sensitivity and enabling directional mapping of dark radiation sources.

Findings

Dark radiation flux can be detected via resonant conversion.

Longitudinal polarization enhances detection sensitivity.

Potential to map dark radiation sources within the galaxy.

Abstract

We present a novel way of probing non-gravitational dark matter interactions: dark astronomy, which leverages the dark radiation emitted by dissipative dark sectors. If the mediator of the dark matter self interactions is a dark photon with a small mass that kinetically mixes with the visible photon, the dark radiation flux becomes accessible to underground experiments. We argue that the emission may be dominantly longitudinally polarized, thereby enhancing the sensitivity of direct detection experiments such as XENON and SENSEI to this signal. We introduce a new detection mechanism based on resonant dark-photon-to-photon conversion at the surface of conducting materials, which offers unique directional sensitivity to dark radiation. This mechanism facilitates the development of experiments that combine dark matter detection techniques with methods of traditional astronomy, opening the possibility to map dark radiation sources within our galaxy.