Measurement of $\Delta m^2_{32}$ and $\sin^2\!\theta_{23}$ using Muon Neutrino and Antineutrino Beams in the NOvA Experiment
NOvA is a long-baseline neutrino oscillation experiment located in the mid-west United States. It consists of two functionally identical tracking calorimeters, known as the near and far detector, that measure neutrino interactions induced by the NuMI beam at baselines of 1~km and 810~km. NuMI can be configured to provide a muon neutrino or antineutrino beam. Analysis of \numu~+~\numubar disappearance allows constraint of the $|\Delta m^2_{32}|$ and \sint oscillation parameters. This thesis presents the first NOvA disappearance results using both neutrino and antineutrino data - previous NOvA analyses have only used neutrino beam data. Two analysis improvements are delineated in dedicated chapters - the design of selection criteria to identify events that are fully contained in the far detector and the optimization of particle identification selection criteria in a multi-dimensional parameter space. The full-detector equivalent beam exposures used for this thesis are $8.85\ti mes 10^{20}$ and $6.91\times 10^{20}$~protons~on~target for neutrino and antineutrino data respectively. Under the assumption of a normal (inverted) neutrino mass hierarchy, analysis of the data gives $\Delta m^2_{32}=+2.49^{+0.09}_{-0.07}\times10^{-3}~\text{eV}^2$ ($\Delta m^2_{32}=-2.54\pm0.08\times10^{-3}~\text{eV}^2$) and $\sin^2\theta_{23} = 0.59\pm0.03$ ($\sin^2\theta_{23} = 0.44\pm0.03$). Maximal mixing ($\sin^2\theta_{23} = 0.5$) is disfavoured at the 1.7~\sig level.