Evidence for Solar Influences on Nuclear Decay Rates

Recent reports of periodic fluctuations in nuclear decay data of certain isotopes have led to the suggestion that nuclear decay rates are being influenced by the Sun, perhaps via neutrinos. Here we present evidence for the existence of an additional periodicity that appears to be related to the Rieger periodicity well known in solar physics.Comment: Presented at the Fifth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 28-July 2, 201

Phenomenology of time-varying nuclear decay parameters

We present a phenomenological analysis of time-varying nuclear decay parameters in order to explain possible variations in nuclear decay rates observed in experiments conducted at Brookhaven National Laboratories, the Physikalisch-Technische Bundesanstalt in Germany, and Purdue University. We explore the implications of a model in which β-decays are modified to a greater degree than α-decays in the context of the PTB 226Ra data, and examine how different phase shifts can arise using the BNL 32Si–32P data as a case study. It is difficult to account for the entire variation observed in the PTB 226Ra data if variations in β-decay are the only source of the observed signal, and we find that phase shifts in experimental data can arise when the isotope in question is part of a decay chain that is in equilibrium. A model where solar neutrinos modify the phase space available to the decay constituents is constructed and explored, in an attempt to reproduce variations in decay rates of the same order of magnitude as those observed in the BNL/PTB/Purdue data sets. This model produces insufficient modifications to the decay rate when short range (\u3c 1 Å) interactions are considered, but suffices if the new interaction has a range on the order of ∼ 1 cm. Experimental consequences of the solar neutrino hypothesis are examined, focusing on the question of how samples undergoing β-decay would perturb their own decay rates. The results of an experiment conducted at NIST to look for such an effect in 198Au are presented, and leave open the possibility of such a modification