MAGNETIC-MOMENT SOLUTION TO THE SOLAR-NEUTRINO PROBLEM, ANTICORRELATION WITH SUNSPOT ACTIVITY AND CHALLENGES FOR FUTURE EXPERIMENTS

The analysis of the most recent solar neutrino data in the light of th e resonant spin flip flavour conversion of neutrinos in the Sun sugges ts the existence of two possible solutions for the solar neutrino prob lem, one of them associated with a neutrino flavour mass square differ ence of the order of 10(-8) eV(2) and the other of the order of 10(-5) eV(2). The magnetic moment is in the range mu(v) = (10(-12) - 10(-11) ) mu(B). In the first possibility the most energetic neutrinos will ha ve their resonance in the solar convective zone. This indicates that t he forthcoming SNO and Icarus experiments are very well placed to test this solution through the anticorrelation effect with sunspot activit y that may be present in the Homestake data but still remains an open question.