Search for periodic modulations of the rate of double- β decay of Mo 100 in the NEMO-3 detector

Double-beta decays of Mo100 from the 6.0195-year exposure of a 6.914 kg high-purity sample were recorded by the NEMO-3 experiment that searched for neutrinoless double-beta decays. These ultrarare transitions to Ru100 have a half-life of approximately 7×1018 years and have been used to conduct the first-ever search for periodic variations of this decay mode. The Lomb-Scargle periodogram technique, and its error-weighted extension, were employed to look for periodic modulations of the half-life. Data show no evidence at the 95% confidence level of modulations with amplitude greater than 2.5% in the frequency range of 0.33225yr-1 to 360yr-1.