The Dark Photon in the PHELEX Experiment

Abstract

This paper presents diurnal measurements of the single-electron count rate in the PHELEX experiment using multi-cathode counters over the period from 2023 to 2026. The results obtained are interpreted as an indication of a possible effect from dark photons with masses ranging from 10 to 40 eV. The correlation of the measured rates in counters with Fe and Al cathodes suggests that the effect does not depend on the magnetic properties of the cathode material. This can be interpreted as an argument against many dark matter models related to magnetic moments. The result, if confirmed in an independent experiment, could narrow the range of possible candidates to those that interact primarily through an electric (or longitudinal) field, insensitive to spin. A dark photon with kinetic mixing fits this description ideally.