New Directions for Axion Searches via Scattering at Reactor Neutrino Experiments

TL;DR

This paper proposes a novel method to search for axion-like particles using nuclear reactors and neutrino detectors, which could surpass current experimental limits in certain mass ranges.

Contribution

It introduces a new experimental approach for ALP detection via reactor-produced ALPs and demonstrates its potential to improve existing constraints.

Findings

Sensitivity exceeds current laboratory limits for ALP-photon couplings.

Forecasts the best laboratory constraints for ALP-electron couplings in sub-MeV mass range.

Potential for near-term experimental implementation at MINER neutrino experiment.

Abstract

Searches for pseudoscalar axion-like-particles (ALPs) typically rely on their decay in beam dumps or their conversion into photons in haloscopes and helioscopes. We point out a new experimental direction for ALP probes through their production via the Primakoff process or Compton-like scattering off of electrons or nuclei. We consider ALPs produced by the intense gamma ray flux available from megawatt-scale nuclear reactors at neutrino experiments through Primakoff-like or Compton-like channels. Low-threshold detectors in close proximity to the core will have visibility to ALP decays and inverse Primakoff and Compton scattering, providing sensitivity to the ALP-photon and ALP-electron couplings. We find that the sensitivity to these couplings at the ongoing MINER neutrino experiment exceeds existing limits set by laboratory experiments and, for the ALP-electron coupling, we forecast the world's best laboratory-based constraints over a large portion of the sub-MeV ALP mass range.