Four-Way Neutrino Oscillations

We present a four-neutrino model with three active neutrinos and one sterile neutrino which naturally has maximal $\nu_\mu\to\nu_\tau$ oscillations of atmospheric neutrinos and can explain the solar neutrino and LSND results. The model predicts $\nu_e \to \nu_\tau$ and $\nu_e \to \nu_\mu$ oscillations in long-baseline experiments with $L/E \gg 1$ km/GeV with amplitudes that are determined by the LSND oscillation amplitude and argument controlled by the atmospheric $\delta m^2$.