Further Evidence Suggestive of a Solar Influence on Nuclear Decay Rates

Abstract

Recent analyses of nuclear decay data show evidence of variations suggestive of a solar influence. Analyses of datasets acquired at the Brookhaven National Laboratory (BNL) and at the Physikalisch-Technische Bundesanstalt (PTB) both show evidence of an annual periodicity and of periodicities with sidereal frequencies in the neighborhood of 12.25 year −1 (at a significance level that we have estimated to be 10 −17 ). It is notable that this implied rotation rate is lower than that attributed to the solar radiative zone, suggestive of a slowly rotating solar core. This leads us to hypothesize that there may be an "inner tachocline" separating the core from the radiative zone, analogous to the "outer tachocline" that separates the radiative zone from the convection zone. The Rieger periodicity (which has a period of about 154 days, corresponding to a frequency of 2.37 year −1 ) may be attributed to an r-mode oscillation with spherical-harmonic indices l = 3, m = 1, located in the outer tachocline. This suggests that we may test the hypothesis of a solar influence on nuclear decay rates by searching BNL and PTB data for evidence of a "Rieger-like" r-mode oscillation, with l = 3, m = 1, in the inner tachocline. The appropriate search band for such an oscillation is estimated to be 2.00-2.28 year −1 . We find, in both datasets, strong evidence of a periodicity at 2.11 year −1 . We estimate that the probability of obtaining these results by chance is 10 −12 .

Concerning the Phases of the Annual Variations of Nuclear Decay Rates

“…We have found evidence, reported in previous publications (Sturrock et al 2010a(Sturrock et al , 2010b, of modulations in decay rates that may be attributable to rotation at or near the solar core. We have also recently found evidence of a Rieger-type modulation that we may attribute to an "inner tachocline" separating the core from the radiative zone (Sturrock et al 2011). These results show that whatever radiation is responsible for influencing decay rates propagates essentially freely through the solar radiative and convection zones, suggesting that some flavor of neutrinos may be responsible for decay-rate variations.…”

“…A framework to describe a possible class of mechanisms is presented in Fischbach et al (2009). We have found evidence, reported in previous publications (Sturrock et al 2010a(Sturrock et al , 2010b, of modulations in decay rates that may be attributable to rotation at or near the solar core. We have also recently found evidence of a Rieger-type modulation that we may attribute to an "inner tachocline" separating the core from the radiative zone (Sturrock et al 2011).…”

“…In our earlier power spectrum analysis (Sturrock et al 2010a), we followed Alburger et al (1986) and considered only the ratio of the 36 Cl and 32 Si decay rates. However, since we are now interested primarily in the phases of the decay-rate oscillations (rather than their amplitudes), it is necessary to consider the two data sets separately.…”

“…We have recently presented evidence that both BNL and PTB measurements also exhibit a periodicity suggestive of the influence of solar rotation-possibly of the solar core (Sturrock et al 2010a(Sturrock et al , 2010b. Such a periodicity would indicate that the radiation is anisotropic, indicating specifically a longitudinal (east-west) asymmetry.…”

Concerning the time dependence of the decay rate of 137Cs

“…To form spectrograms, we first prepare the data by means of the RONO (Rank-Order NOrmalization) operation (Sturrock et al, 2011a) that maps the measurements onto a normal distribution, as is appropriate for power-spectrum analyses such as the Lomb-Scargle procedure (Lomb, 1976;Scargle, 1982) or a likelihood procedure (Sturrock et al, 2006). We then carry out a sequence of likelihood power-spectrum analyses of sections of the data.…”