Completing our Picture of the Neutrino

Speaker:

Josh Spitz, Norman M. Leff, professor of physics, Michigan University

Description:

Nearly 90 years after its proposed existence, the neutrino remains largely mysterious and elusive. We don't know if matter neutrinos behave differently than antimatter neutrinos, which is the heaviest, or how many types of neutrinos there are.

The MiniBooNE short-baseline neutrino experiment has recently reported a significant (4.5sigma) excess of electron-neutrino- like events in an originally muon-neutrino beam. An oscillation interpretation of this data would require at least four neutrino types and indicate new physics beyond the three neutrino paradigm. MiniBooNE is not alone in its anomalous observations of possible new neutrino mixing, as there may be hints from other experiments as well. This talk will discuss the recent MiniBooNE result, possible non-neutrino interpretations, and prospects for future accelerator-based measurements. In particular, Fermilab's Short-Baseline Neutrino (SBN) and the J-PARC Sterile Neutrino Search at the J-PARC Spallation Neutron Source (JSNS2) experiments will directly address these anomalies in the next few years.

Along with discussing the recent MiniBooNE results and introducing SBN and JSNS2, I will touch on the first measurement of the 236 MeV kaon decay-at-rest neutrino, recently performed with MiniBooNE. I will emphasize the significance of this and future studies in terms of elucidating both the neutrino-nucleus interaction and oscillations.