The Gallium Anomaly had been used to support the idea of sterile neutrinos. But it turns out that the anomaly was just a result of a flawed calculation of the Standard Model expectation. The correct calculation shows no anomaly in independent experimental measurements.
The Gallium Anomaly is the disagreement between the measured capture rate of neutrinos by 71Ga and the rate theoretically expected from the electron capture decay of 71Ge. The experimental measurements were performed with intense artificial sources.
In the present work we consider the sun as a neutrino source that can be calibrated via the fundamental, standard-model neutrino-electron elastic scattering reaction in terrestrial detectors. The result is found to be not anomalous, with good agreement between the measured value of 66.1 ± 3.1 SNU from SAGE and Gallex/GNO, and the total measured source strengths of solar sources, 67.5 +1.4 −1.1 SNU. It may be concluded that neither the 71Ga charged-current cross section nor gallium experiment extraction and counting efficiencies account for the Gallium Anomaly.
Steven R. Elliott, R. G. Hamish Robertson, "Gallium Anomaly and Solar Neutrinos"arXiv:2610.22219 (October 15, 2026).
Another paper confirms again that muon g-2 doesn't show a discrepancy between theoretical predictions of it and experimental measurements of it at extreme precision. The muon g-2 anomaly was also due to a flawed calculation of the Standard Model expectation.
Progress is also being made in the tau g-2 calculation, but the experimental measurements of tau g-2 are too imprecise to meaningfully compare them to the theoretical calculation.
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