Overview
- MicroBooNE reports no evidence for a fourth neutrino and rejects the single light 3+1 scenario at about 95% confidence.
- Using one liquid-argon detector exposed to Fermilab’s Booster and NuMI beams from 2015 to 2021, MicroBooNE excludes nearly the entire previously favored region.
- KATRIN’s precision beta‑decay measurements find no sign of a sterile state and further narrow the remaining parameter space.
- The null results remove a leading explanation for LSND and MiniBooNE anomalies, which scientists say still require alternative theories.
- Teams are analyzing remaining data and expect cross‑checks from other short‑baseline experiments, with techniques feeding into future efforts such as DUNE.