Constraints on Neutrino Oscillations Using 1258 Days of Super-Kamiokande Solar Neutrino Data

TL;DR

This study uses 1258 days of Super-Kamiokande data to search for neutrino oscillations, finding no significant zenith angle variation or spectrum distortion, thus constraining neutrino properties and identifying two large mixing regions.

Contribution

It provides flux-independent constraints on neutrino mixing and mass difference, and identifies two allowed regions at large mixing using extensive solar neutrino data.

Findings

No significant zenith angle variation observed.

Spectrum distortion constraints neutrino oscillation parameters.

Two large mixing regions are compatible with data.

Abstract

We report the result of a search for neutrino oscillations using precise measurements of the recoil electron energy spectrum and zenith angle variations of the solar neutrino flux from 1258 days of neutrino-electron scattering data in Super-Kamiokande. The absence of significant zenith angle variation and spectrum distortion places strong constraints on neutrino mixing and mass difference in a flux-independent way. Using the Super-Kamiokande flux measurement in addition, two allowed regions at large mixing are found.