Shining Light on Cosmogenic Axions with Neutrino Experiments

TL;DR

This paper proposes using neutrino experiments to detect relativistic axions from cosmological sources via mono-energetic photon signals, opening new avenues for axion discovery beyond traditional dark matter searches.

Contribution

It introduces a novel method to detect boosted axions using existing neutrino detectors through their photon absorption signature, expanding the search parameter space.

Findings

Neutrino experiments can detect relativistic axions via mono-energetic photons.

The proposed method covers parameter ranges complementary to existing axion searches.

Existing and upcoming neutrino facilities can potentially discover boosted axions.

Abstract

While most searches for cosmic axions so far focused on their cold relics as (a component of) dark matter, various well-motivated cosmological sources can produce "boosted" axions that remain relativistic today. We demonstrate that existing/upcoming neutrino experiments such as Super-Kamiokande, Hyper-Kamiokande, DUNE, JUNO, and IceCube can probe such energetic axion relics. The characteristic signature is the mono-energetic single photon signal from axion absorption induced by the axion-photon coupling. This proposal offers to cover parameter ranges that are complementary to existing axion searches and provides new opportunities for discovery with neutrino facilities.