Implications of new theoretical calculations on reactor antineutrino and gallium anomaliesONLINE ONLY

The reactor antineutrino and gallium anomalies have been long unexplained. Possible explanations for both of these anomalies include new physics, such as the existence of one or more eV-scale sterile neutrinos. However, the previous theoretical calculations, which fail to replicate the experimental results, rely on many simplifying approximations.

In the case of the reactor anomaly, the individual antineutrino spectra have been previously estimated using so-called allowed or unique forbidden approximations. However, calculating these spectra using the nuclear shell model and the full forbidden beta decay formalism results in significant differences in the individual spectra. Large-scale shell model calculations are also employed in order to derive an updated estimate for the neutrino-nucleus scattering cross section for scattering off 71Ga. The statistical significance of the gallium anomaly is reduced by the updated calculations.

Zoom link