Oscillation Solutions to Solar Neutrino Problem

TL;DR

This paper reviews various oscillation solutions to the Solar Neutrino Problem using Superkamiokande data, highlighting the viability of vacuum oscillations and discussing seasonal variations in neutrino flux, with no definitive evidence for oscillation yet.

Contribution

It provides a comprehensive review of four oscillation solutions to the Solar Neutrino Problem in light of recent data, emphasizing the potential of vacuum oscillations and seasonal variation predictions.

Findings

EIS VO is strongly disfavoured by global rates.

Vacuum oscillations explain high-energy excess and predict seasonal variations.

No direct evidence for neutrino oscillation has been observed.

Abstract

The current status of oscillation solutions to the Solar Neutrino Problem is reviewed. Four oscillation solutions are discussed in the light of 708d Superkamiokande data: MSW, Just-So VO, VO with Energy-Independent Suppression (EIS) and Resonant-Spin-Flavor-Precession (RSFP). Only EIS VO is strongly disfavoured by the global rates, mostly due to the Homestake data. Vacuum oscillations give an interesting solution which explains high-energy excess of events observed by Superkamiokande and predicts {\em semi-annual} seasonal variation of $Be$-neutrino flux. There are indications to these variations in the GALLEX and Homestake data. No direct evidence for oscillation is found yet.