XENONnT detector records the faintest neutrino collisions ever observed

The XENON collaboration disclosed via a webinar that its XENONnT detector, buried deep under a mountain in central Italy, has observed the faintest neutrino-electron collisions ever recorded. The signal, attributed to solar neutrinos, passes a statistical test with a probability of less than one in a million of being a random fluctuation. Co-lead analyst Masatoshi Kobayashi called the result an important milestone for low-energy neutrino physics, while Luca Grandi described it as proof of the experiment’s technological maturity.

Researchers note that this level of sensitivity brings dark-matter experiments close to the so-called “neutrino floor,” where solar-neutrino background could mask potential dark-matter signals. Nonetheless, the detection demonstrates the progress made in ultra-low-background detectors and sets a new benchmark for particle-physics research.