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 (vacuum 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 {\it three} neutrinos are maximally mixed. It is shown that the values of $\Delta m^2$ 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 $\Delta m_{31}^2\simeq 10^{-2}{\mathrm{eV}}^2$ for the atmospheric neutrinos and $\Delta m_{21}^2\simeq 10^{-10}{\mathrm{eV}}^2$ for solar neutrinos in the maximally mixed three-generation scheme.

Comments: Revtex file, 11 pages + 3 figures (included). The postscript file of text and figures is available at ftp://toxd01.to.infn.it/pub/giunti/1994/dftt-54-94/dftt-54-94.ps.Z