Sterile Neutrino Search with MicroBooNE's Electron Neutrino Disappearance Data.

Abstract

A sterile neutrino is a well motivated minimal new physics model that leaves an imprint in neutrino oscillations. Over the last two decades, a number of hints pointing to a sterile neutrino have emerged, many of which are pointing near m_{4}∼1 eV. Here, we show how MicroBooNE data can be used to search for electron neutrino disappearance using each of their four analysis channels. We find a hint for oscillations with the highest single channel significance of 2.4σ (using the Feldman-Cousins approach) coming from the Wire-Cell analysis and a simplified treatment of the experimental systematics. The preferred parameters are sin^{2}(2θ_{14})=0.35_{-0.16}^{+0.19} and Δm_{41}^{2}=1.25_{-0.39}^{+0.74} eV^{2}. This region of parameter space is in good agreement with existing hints from source experiments, is at a similar frequency but higher mixing than indicated by reactor antineutrinos, and is at the edge of the region allowed by solar neutrino data. Existing unanalyzed data from MicroBooNE could increase the sensitivity to the >3σ level.