Physicists are stumped by an old Soviet experiment that could point to a new fundamental particle, possibly a sterile neutrino, to explain unexpected findings. The gallium anomaly, observed in experiments at the Baksan Neutrino Observatory in Russia’s Caucasus Mountains, has confounded scientists for decades. Recent studies have ruled out errors in measurements, leading to the possibility of a groundbreaking discovery or a new type of neutrino. The unusual results, still unexplained, suggest that something unique is happening with neutrinos. This anomaly could shed light on dark matter and challenge established theories in particle physics and cosmology.
https://www.quantamagazine.org/what-could-explain-the-gallium-anomaly-20240712/