Evidence for Time-Varying Nuclear Decay Rates: Experimental Results and Their Implications for New Physics

Unexplained annual variations in nuclear decay rates have been reported in recent years by a number of groups. We show that data from these experiments exhibit not only variations in time related to Earth-Sun distance, but also periodicities attributable to solar rotation. Additionally, anomalous decay rates coincident in time with a series of solar flares in December 2006 also point to a solar influence on nuclear decay rates. This influence could arise from some flavor of solar neutrinos, or through some other objects we call "neutrellos" which behave in some ways like neutrinos. The indication that neutrinos or neutrellos must interact weakly in the Sun implies that we may be able to use data on time-varying nuclear decay rates to probe the interior of the Sun, a technique which we may call "helioradiology".