FUTURE SOLAR-NEUTRINO SPECTROSCOPY AND NEUTRINO PROPERTIES

The GALLEX result, together with the constraints from the observed value of the solar constant, yields strong limits on the flux of neutrinos from the pp-I termination of the pp-chain, 62 less-than-or-equal-to PHI(pp+pep) [10(9) cm-2 s-1] less-than-or-equal-to 65, provided that neutrinos are standard. This conclusion is essentially independent of solar models and it implies that the pp-chain is shifted towards the pp-I termination, in comparison with the SSM prediction. As a consequence, we derive an upper bound on Berillium neutrinos: PHI(Be) less-than-or-equal-to 3 x 10(9) cm-2 s-1, the violation of this bound being a clear signal of non-standard neutrino properties. We also find that, for a large class of solar models built so as to enhance the pp-I termination, the pep-neutrino flux is stable around PHI(pep) almost-equal-to 1.5 x 10(8) cm-2 s-1. Detection of pep neutrinos will clearly discriminate standard neutrinos against MSW oscillations, this latter model giving PHI(pep)MSW less-than-or-equal-to 3 x 10(7) cm-2 s-1.