Light Shining Through a Thin Wall: Evanescent Hidden Photon Detection
Dr. Ryan Janish
FermiLab
Photon regeneration experiments test for mixing between photons and a feebly-coupled new state by trapping photons behind a barrier and monitoring to see how many pass through. This leakage would be caused by photons mixing into an untrapped new state and then mixing back into photons. Current and prior searches have had significant sensitivity only to new states with a mass below the frequency of the source photons. For radio frequency (RF) experiments, that is roughly m < 0.01 meV. I will demonstrate that by using thin barriers this reach can be dramatically extended, up to 0.1 eV in the RF case, without increasing the energy of the source photons. Such an arrangement allows photons to traverse the barrier by mixing into an exponentially decaying evanescent mode of the new state, as opposed to a propagating mode. I will outline a proposed search for kinetically-mixed hidden photons using superconducting RF cavities separated by a thin barrier, which will have leading reach for hidden photon masses between 0.01 meV and 0.1 eV.