Observation of Muon Neutrino Disappearance with the MINOS Detectors in the NuMI Neutrino Beam

The Main Injector Neutrino Oscillation Search (MINOS) is a long baseline neutrino oscillation experiment that uses a muon-neutrino beam produced by the Neutrinos at the Main Injector (NuMI) facility at Fermi National Accelerator Laboratory (FNAL). The experiment is conducted with a pair of functionally identical detectors, located at two sites, the Near Detector (ND) at FNAL and the Far Detector (FD) in the Soudan Underground Laboratory in Minnesota. The NuMI beamline and the 735~km long-baseline allow a search for $\nu_{\mu}$ disappearance, a rigorous test of the oscillation hypothesis, and a measurement of the $\Delta m^2_{32}$ and $\sin^2{(2\theta_{23})}$ mixing parameters studied previously with atmospheric neutrinos and by the K2K experiment. I will describe the MINOS experiment and discuss highlights from the second year of beam data-taking before presenting a measurement of $\Delta m^2_{32}$ and $\sin^2{(2\theta_{23})}$ based on an exposure of $2.5 \times 10^{20}$~POT (protons on target). I will conclude with a discussion of the experiment's future prospects, including a search for sub-dominant $\nu_{\mu} \rightarrow \nu_{e}$ transitions.