What causes the short-baseline neutrino anomalies?
In plain words
LSND and MiniBooNE saw extra electron-like events, and gallium detectors saw too few neutrino captures. These do not fit the three-neutrino picture.
Precise statement
Explain the LSND (1995) and MiniBooNE electron-like excesses and the gallium deficit in a single consistent framework, or show they have separate conventional origins. An answer is the mechanism (sterile oscillation, decaying heavy states, new interactions, or background and cross-section mismodeling) consistent with disappearance limits.
What would settle it
The Fermilab SBN program (SBND, MicroBooNE, ICARUS) measuring $\nu_e$ appearance and $\nu_\mu$ disappearance with one technology at several baselines.
Status in the literature
Unverified note
MicroBooNE (Nature, December 2025) excludes a single light sterile neutrino explanation of LSND and MiniBooNE at 95 percent CL.
Related problems
- More general than Does an eV-scale sterile neutrino exist?
- More general than Why do gallium detectors see about 20 percent fewer neutrino captures?
- More general than What is the source of the MiniBooNE low-energy excess?