The Gallium Anomaly Uncovering a New Particle in Physics

The Baksan Experiment on Sterile Transitions (BEST) finds evidence of the sterile neutrino, a hypothetical particle that interacts only via gravity.

Scientists have confirmed possible evidence of a new elementary particle, the sterile neutrino. These particles, if they exist, interact only via gravity, not any of the other forces in the Standard Model of Particle Physics.

The results from the Baksan Experiment on Sterile Transitions (BEST) confirm an anomaly found in earlier solar neutrino source experiments. BEST irradiated a tank of gallium, a soft silvery metal that is liquid at room temperature, using an intense source of neutrinos from decays of radioactive chromium. The neutrinos react in the gallium to produce the isotope germanium 71. This isotope can be extracted from the gallium and counted.

The researchers found significantly smaller amounts of germanium than expected based on known nuclear physics. Scientists had found a similar gallium anomaly in a precursor experiment