Weakly Interacting Sub‐eV Particle Searches

We make use of the generation‐regeneration or “light shining through a wall” technique in searches for optical‐wavelength photons mixing with hypothetical hidden‐sector paraphotons in the mass range between 10−5 and 10−2 electron volts for a mixing parameter greater than 10−7 and in sensitive searches for scalar and pseudoscalar coupling of photons to light neutral bosons in the mass range of approximately 1.0 milli‐electron volts and coupling strength greater than 10−6 GeV−1. Additionally, there is an effort underway to use photons in the microwave region using this same technique to make a more sensitive measurement in the mass range of approximately 0.1 milli‐electron volts. The equipment in the latter effort will be used to search for galactic halo axions in this same mass range.