THE PP REACTION IN THE SUN AND SOLAR NEUTRINOS

We study the dependence of the solar structure and of the expected neutrino fluxes on the variation of the astrophysical S-factor for the pp reaction. In such a way we obtain a sample of self-consistent solar structures which allow to investigate the consequence of varying the central solar temperature T(c). We show that the distribution of physical parameters in such ''pseudo-solar models'' is governed by severe theoretical constraints. On this basis one finds that there is no value of S(pp) or of T(c) which can account simultaneously for the results of the Homestake, Kamioka and Gallex experiments.