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 $L\mathrm{/}E\gg 1$ km/GeV with amplitudes that are determined by the LSND oscillation amplitude and argument controlled by the atmospheric $\delta m^2$.