Detecting Dark Photon with Reactor Neutrino Experiments

Abstract

We propose to search for light $U(1)$ dark photons, $A'$, produced via kinetically mixing with ordinary photons via the Compton-like process, $γe^- \rightarrow A' e^-$, in a nuclear reactor and detected by their interactions with the material in the active volumes of reactor neutrino experiments. We derive 95\% confidence-level upper limits on $ε$, the $A'$-$γ$ mixing parameter, $ε$, for dark-photon masses below 1$\sim$MeV of $ε~< ~1.3\times 10^{-5}$ and $ε~<~2.1\times 10^{-5}$, from NEOS and TEXONO experimental data, respectively. This study demonstrates the applicability of nuclear reactors as potential sources of intense fluxes of low-mass dark photons.