Mikheyev-Smirnov-Wolfenstein effect on neutrino decay

It has early been pointed out by R. S. Raghavan et al that in solar matter, conversion of the electron neutrino to a "heaver" flavor by the MSW effect can catalyze neutrino decay in the small mixing angle MSW solution. Since recent results on solar neutrinos provide hints that the large mixing angle MSW solution could be correct, we present a detailed study of the MSW effe ct with neutrino decay for both small and large mixing angles. The lower li mit for the lifetime of 10 MeV neutrinos is estimated to be tau (10 MeV) gr eater than or similar to 10(3)s.