Atmospheric neutrino problem in maximally-mixed three generations of neutrinos

Abstract Motivated by the indication that both the atmospheric and the solar neutrino puzzles may simultaneously be solved by (vaccuum as well as matter-induced resonant) oscillations of two generations of neutrinos with large mixing, we have analyzed the data on the atmospheric and solar neutrinos assuming that all three neutrinos are maximally mixed. It is shown that the values of Δm2 obtained from the two-generation analyses are still valid even in the three-generation scheme, i.e. the two puzzles can be solved simultaneously if Δm 31 2 ⋍ 10 −2 eV 2 for the atmospheric neutrinos and Δm 21 2 ⋍ 10 −10 eV 2 for solar neutrinos in the maximally mixed three-generation scheme.