Interpreting the atmospheric neutrino anomaly

We suggest that the atmospheric neutrino anomaly observed in the Super-Kamiokande (and other) experiments results from the combined effects of muon-neutrino to tau-neutrino oscillations with a Δm2 value of approximately 0.4 eV2 and oscillations between muon neutrinos and electron neutrinos (and vice-versa) with 0.0001<Δm2<0.001 eV2. With an appropriate choice of a three-neutrino mixing matrix, such a hypothesis is consistent with essentially all neutrino observations.