Detecting Dark Photons from Atomic Rearrangement in the Galaxy

TL;DR

This paper proposes a novel dark matter detection method involving atomic rearrangement in the galaxy, which produces detectable dark photons that can be observed in existing neutrino experiments, offering new avenues for dark sector exploration.

Contribution

It introduces a new atomic process signature for dark matter detection via dark photon emission, with detailed analysis of experimental bounds and future prospects.

Findings

Dark photons from atomic rearrangement can be detected by neutrino observatories.

Current data constrains the model parameters for GeV-scale dark matter.

Future detectors could improve sensitivity to this dark matter signature.

Abstract

We study a new dark sector signature for an atomic process of "rearrangement" in the galaxy. In this process, a hydrogen-like atomic dark matter state together with its anti-particle can rearrange to form a highly-excited bound state. This bound state will then de-excite into the ground state emitting a large number of dark photons that can be measured in experiments on Earth through their kinetic mixing with the photon. We find that for DM masses in the GeV range, the dark photons have enough energy to pass the thresholds of neutrino observatories such as Borexino and Super-Kamiokande that can probe for our scenario even when our atomic states constitute a small fraction of the total DM abundance. We study the corresponding bounds on the parameters of our model from current data as well as the prospects for future detectors.