Seasonal and Energy Dependence of Solar Neutrino Vacuum Oscillations

TL;DR

This paper analyzes solar neutrino data to understand vacuum oscillations, considering seasonal and energy variations, and finds parameters favoring active neutrino oscillations with bi-maximal mixing, disfavoring sterile neutrinos.

Contribution

It provides a comprehensive global analysis of solar neutrino oscillations incorporating recent Super-Kamiokande data, including seasonal and energy dependence, and refines oscillation parameters.

Findings

Best fit m^2 = 4.42^{-10} eV^2

Oscillations favor active neutrinos with bi-maximal mixing

Sterile neutrino oscillations are disfavored

Abstract

We make a global vacuum neutrino oscillation analysis of solar neutrino data, including the seasonal and energy dependence of the recent Super-Kamiokande 708-day results. The best fit parameters for \nu_e oscillations to an active neutrino are \delta m^2 = 4.42\times10^{-10} eV^2, \sin^2 2\theta = 0.93. The allowed mixing angle region is consistent with bi-maximal mixing of three neutrinos. Oscillations to a sterile neutrino are disfavored. Allowing an enhanced hep neutrino flux does not significantly alter the oscillation parameters.