Nitish Nayak (BNL), "MicroBooNE Sterile Neutrino Results"

Monday 8 Dec 2025, 12:45 → 13:55 US/Eastern

D-122 (SBU Physics building)

Ciro Riccio (Stony Brook University (US)), Hannah Arnold (Stony Brook University)

12:45 → 13:30 Search for eV-scale Sterile Neutrinos in a 3+1 Model using Two Beams at MicroBooNE

The existence of three distinct neutrino flavors with oscillations between them has been shown by several experiments over the past decades. However, several observations inconsistent with this picture have motivated the hypothesis that an additional neutrino state exists which does not interact directly with matter, i.e a sterile neutrino, but nevertheless undergoes oscillations with the original three flavors (3+1 oscillations). These observations include the LSND and MiniBooNE experiments that are consistent with an anomalous appearance of electron neutrinos in a muon neutrino beam at short baselines. Similarly, observations by GALLEX, BEST and SAGE ("gallium anomaly") can be explained by an anomalous disappearance of electron neutrinos from a radioactive source. The MicroBooNE experiment, which consists of an 85-ton liquid argon time projection chamber sitting in the same beamline as MiniBooNE can help resolve this picture.In this talk, I will describe the latest results from MicroBooNE searching for an eV-scale sterile neutrino in a 3+1 model. This result incorporates data from two neutrino beams that MicroBooNE is sensitive to, one on-axis (BNB) and another off-axis (NuMI) at an angle of 8 degrees. This setup helps break degeneracies between electron-neutrino appearance and disappearance and thus extend our reach at 95% CL to most of the regions allowed by the LSND/MiniBooNE/Gallium experiments. We find no evidence for such oscillations and as a result, place world-leading limits on the 3+1 model by a single experiment. Our results therefore indicate strongly that previous anomalous observations cannot be explained by this model and therefore motivate searching for alternative explanations, especially from the ongoing SBN program at Fermilab.

Speaker: Bannanje Nitish Nayak