Oscillation Solutions to Solar Neutrino Problem

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.