A Measurement of Atmospheric Neutrino Oscillation Parameters by Super-Kamiokande I

We present a combined analysis of fully-contained, partially-contained and upward-going muon atmospheric neutrino data from a 1489 day exposure of the Super--Kamiokande detector. The data samples span roughly five decades in neutrino energy, from 100 MeV to 10 TeV. A detailed Monte Carlo comparison is described and presented. The data is fit to the Monte Carlo expectation, and is found to be consistent with neutrino oscillations of $\nu_\mu \leftrightarrow \nu_\tau$ with $\sin^22\theta > 0.92$ and $1.5\times 10^{-3} < \Delta m^2 < 3.4\times 10^{-3}{\rm eV}^2$ at 90% confidence level.