Constraints on Galactic Dark Photons from a DALI Prototype

Abstract

An analysis of 36 hours of data from a DALI haloscope reveals no statistically significant excess attributable to dark-photon dark matter. We therefore set new constraints in the 6.88691--6.91792 GHz band, reaching a dark-photon-to-photon kinetic mixing strength of $\chi \lesssim 6.8\times 10^{-14}$ at $28.54\mu \mathrm{eV}$. To our knowledge, this result established the strongest laboratory-based exclusion limit in this frequency range.

5 pages, 5 figures