Generalized Lomb–Scargle analysis of 22 years of super-Kamiokande solar $$^8$$ 8 B neutrino data

Abstract

Abstract We apply the generalized Lomb–Scargle periodogram to 22 years data of solar $$^{8}$$ 8 B neutrino fluxes detected by Super-Kamiokande. The primary motivation of this work was to check if the sinusoidal modulation at a frequency of 9.43/year (with a period of 38 days), which we had found to be marginally significant with the first 5 years of Super-K data, persists, with the accumulated data. We use four different metrics for the calculation of significance of any peaks in the Lomb–Scargle periodogram, which could be indicative of periodicities. We do not find any evidence for periodicity at the aforementioned frequency or any other frequency with the updated data. Therefore, the observed peak at 9.43/year with the first 5 years of Super-Kamiokande data was only a statistical fluctuation and its significance is negligible with the updated data.