Cryogenic resonant microwave cavity searches for hidden sector photons

TL;DR

This paper reports a cryogenic microwave cavity experiment that sets new upper limits on hidden sector photon kinetic mixing, advancing the search for weakly interacting particles potentially related to dark matter.

Contribution

It introduces a cryogenic resonant microwave cavity setup for hidden photon detection, achieving more stringent bounds than previous cavity experiments in the same mass range.

Findings

Limited hidden photon kinetic mixing parameter to < 1.7×10⁻⁷ at 53 μeV mass.

Established new constraints on hidden sector photons as cold dark matter.

Demonstrated the effectiveness of cryogenic cavities in weakly interacting particle searches.

Abstract

The hidden sector photon is a weakly interacting hypothetical particle with sub-eV mass that kinetically mixes with the photon. We describe a microwave frequency light shining through a wall experiment where a cryogenic resonant microwave cavity is used to try and detect photons that have passed through an impenetrable barrier, a process only possible via mixing with hidden sector photons. For a hidden sector photon mass of 53 $\mu$eV we limit the hidden photon kinetic mixing parameter $\chi < 1.7\times10^{-7}$, which is an order of magnitude lower than previous bounds derived from cavity experiments in the same mass range. In addition, we use the cryogenic detector cavity to place new limits on the kinetic mixing parameter for hidden sector photons as a form of cold dark matter.