Search for light sterile neutrinos with two neutrino beams at MicroBooNE.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41339505.
- Also identified by DOI 10.1038/s41586-025-09757-7 and PMC identifier 12675295.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The existence of three distinct neutrino flavours, ν<sub>e</sub>, ν<sub>μ</sub> and ν<sub>τ</sub>, is a central tenet of the Standard Model of particle physics<sup>1,2</sup>. Quantum-mechanical interference can allow a neutrino of one initial flavour to be detected sometime later as a different flavour, a process called neutrino oscillation. Several anomalous observations inconsistent with this three-flavour picture have motivated the hypothesis that an additional neutrino state exists, which does not interact directly with matter, termed as 'sterile' neutrino, ν<sub>s</sub> (refs. <sup>3-9</sup>). This includes anomalous observations from the Liquid Scintillator Neutrino Detector (LSND)<sup>3</sup> experiment and Mini-Booster Neutrino Experiment (MiniBooNE)<sup>4,5</sup>, consistent with ν<sub>μ</sub> → ν<sub>e</sub> transitions at a distance inconsistent with the three-neutrino picture. Here we use data obtained from the MicroBooNE liquid-argon time projection chamber<sup>10</sup> in two accelerator neutrino beams to exclude the single light sterile neutrino interpretation of the LSND and MiniBooNE anomalies at the 95% confidence level (CL). Moreover, we rule out a notable portion of the parameter space that could explain the gallium anomaly<sup>6-8</sup>. This is one of the first measurements to use two accelerator neutrino beams to break a degeneracy between ν<sub>e</sub> appearance and disappearance, which would otherwise weaken the sensitivity to the sterile neutrino hypothesis. We find no evidence for either ν<sub>μ</sub> → ν<sub>e</sub> flavour transitions or ν<sub>e</sub> disappearance that would indicate non-standard flavour oscillations. Our results indicate that previous anomalous observations consistent with ν<sub>μ</sub> → ν<sub>e</sub> transitions cannot be explained by introducing a single sterile neutrino state.