Experimental probes of axions

TL;DR

This paper reviews experimental methods for detecting axions, focusing on electromagnetic techniques like resonant cavities and photon-axion oscillations, to probe their tiny couplings from astrophysical and laboratory sources.

Contribution

It summarizes recent experimental approaches and results in axion searches using electromagnetic phenomena, highlighting the diversity of techniques employed.

Findings

Detection limits for axion-photon coupling constants

Recent experimental constraints on axion properties

Potential for future laboratory and astrophysical searches

Abstract

Experimental searches for axions or axion-like particles rely on semiclassical phenomena resulting from the postulated coupling of the axion to two photons. Sensitive probes of the extremely small coupling constant can be made by exploiting familiar, coherent electromagnetic laboratory techniques, including resonant enhancement of transitions using microwave and optical cavities, Bragg scattering, and coherent photon-axion oscillations. The axion beam may either be astrophysical in origin as in the case of dark matter axion searches and solar axion searches, or created in the laboratory from laser interactions with magnetic fields. This note is meant to be a sampling of recent experimental results.