NO MIKHEYEV-SMIMOV-WOLFENSTEIN EFFECT IN MAXIMAL MIXING

We investigate the possible influence of the MSW effect on the expecta tions for the solar neutrino experiments in the maximal mixing scenari o suggested by the atmospheric neutrino data. A direct numerical calcu lation of matter induced effects in the Sun shows that the naive vacuu m predictions are left completely undisturbed in the particular case o f maximal mixing, so that the MSW effect turns out to be unobservable. We give a qualitative explanation of this result.