Abstract:
We analyze the atmospheric neutrino data in the context of three flavor neutrino oscillations taking account of the matter effects in the Earth. With the hierarchy among the vacuum mass eigenvalues [Formula presented], the solution of the atmospheric neutrino problem depends on [Formula presented] and the [Formula presented] and [Formula presented] mixing angles [Formula presented] and [Formula presented]. Whereas the sub-GeV atmospheric neutrino data imposes only a lower limit on [Formula presented], the zenith-angle-dependent suppression observed in the multi-GeV data limits [Formula presented] from above also. The allowed regions of the parameter space are strongly constrained by the multi-GeV data. Combined with our earlier solution to the solar neutrino problem which depends on [Formula presented] and the [Formula presented] and [Formula presented] mixing angles [Formula presented] and [Formula presented], we have obtained the ranges of values of the five neutrino parameters which solve both the solar and the atmospheric neutrino problems simultaneously. © 1997 The American Physical Society.