PHELEX: Two Series of Measurements in the Search for Dark Photons

Abstract

The results of measurements in two series, each series of 4 Runs and about 50 days each Run, are presented. A multi-cathode counter with an iron cathode is used in these measurements. In both series we have observed some excess in count rates in sidereal time while no excess has been observed in terrestrial time. In the first series from 27.12.22 to 24.07.23 we have observed the excess in the period between 8 a.m. and 12 a.m. of sidereal time with a confidence level more than 6 \sigma, in the second series from 21.09.23 to 03.04.24 in the period between 6 p.m. and 10 p.m. of sidereal time with a confidence level more than 4 \sigma. The fact that in terrestrial time we do not observe a similar effect as in sidereal time suggests that probably this effect is of galactic origin and that this may be caused by dark photons. Future steps are suggested to validate these results.