Search for Dark Photons with Superconducting Radio Frequency Cavities

We conduct the first light-shining-through-wall (LSW) search for dark photons using two state-of-the-art high-quality-factor superconducting radio frequency (SRF) cavities -Dark SRF-and report the results of its pathfinder run. Our new experimental setup enables improvements in sensitivity over previous searches and covers new dark photon parameter space. We design delicate calibration and measurement protocols to utilize the high -Q setup at Dark SRF. Using cavities operating at 1.3 GHz, we establish a new exclusion limit for kinetic mixing as small as & epsilon; = 1.6 x 10-9 and provide the world's best constraints on dark photons in the 2.1 x 10-7-5.7 x 10-6 eV mass range. Our result is the first proof of concept for the enabling role of SRF cavities in LSW setups, with ample opportunities for further improvements. In addition, our data set a competitive lab-based limit on the standard model photon mass by searching for longitudinal photon polarization.

Automated summary

The study conducts the first light-shining-through-wall (LSW) search for dark photons using high-quality-factor superconducting radio frequency (SRF) cavities called Dark SRF. They establish a new exclusion limit and provide the world's best constraints on dark photons. This research serves as a proof of concept for the role of SRF cavities in LSW setups.