Searching for Dark Photons with Existing Haloscope Data

TL;DR

This paper demonstrates how existing axion haloscope data can be repurposed to set competitive limits on dark photon parameters, significantly enhancing dark matter search sensitivity without new experiments.

Contribution

It introduces a method to convert haloscope axion exclusion limits into dark photon constraints and provides the accompanying code for this analysis.

Findings

Achieved around four orders of magnitude improvement in dark photon exclusion sensitivity.

Provided a practical framework for repurposing existing haloscope data for dark photon searches.

Published limits on the kinetic mixing coefficient between dark photons and photons.

Abstract

The dark (or hidden) photon is a massive U(1) gauge boson theorized as a dark force mediator and as a dark matter candidate. Dark photons can be detected with axion cavity haloscopes by probing for a power excess caused by the dark photon's kinetic mixing with Standard Model photons. Haloscope axion exclusion limits may therefore be converted into competitive dark photon parameter limits via the calculation of a corresponding dark photon to photon coupling factor. This calculation allows for an improvement in sensitivity of around four orders of magnitude relative to other dark photon exclusions and may be attained using existing data. We present how one converts haloscope axion search limits and a summary of relevant experimental parameters from published searches. In addition, we have included the code that can be used to generate our dark photon exclusion limits for the cases described in this paper. Finally, we present limits on the kinetic mixing coefficient between dark photons and the Standard Model photons based on existing haloscope axion searches.