ABSTRACT
The present status of all four running solar neutrino experiments is reviewed. Updated results from the Chlorine, Kamiokande and SAGE detectors are presented along with the first result from the GALLEX detector [83 ± 19 (stat.) ± 8 (syst.) SNU]. This number, while consistent with the presence of the full pp neutrino flux as predicted by the Standard Solar Model, confirms the reduced fluxes of high energy solar neutrinos observed in the Chlorine and Kamiokande experiments. Possible scenarios (non-standard solar models, neutrino mixing, neutrino decay and the interaction of magnetic fields in the solar convective zone with a possible magnetic moment of the neutrino) are discussed in order to explain the deviations between the Standard Solar Model predictions and the actual experimental data.
