We report constraints on antineutrino oscillation parameters that were obtained by using the two MINOS detectors to measure the 7% muon antineutrino component of the NuMI neutrino beam. In the Far Detector, we select 130 events in the charged-current muon antineutrino sample, compared to a prediction of $136.4\pm 11.7(\mathrm{stat}{)}_{-8.9}^{+10.2}(\mathrm{syst})$ events under the assumption $|\Delta {\overline{m}}^2|=2.32\times {10}^{-3}{\mathrm{eV}}^2$, ${sin}^2(2\overline{\theta })=1.0$. Assuming no oscillations occur at the Near Detector baseline, a fit to the two-flavor oscillation approximation constrains $|\Delta {\overline{m}}^2|<3.37\times {10}^{-3}{\mathrm{eV}}^2$ at the 90% confidence level with ${sin}^2(2\overline{\theta })=1.0$.

• Received 6 August 2011

DOI:https://doi.org/10.1103/PhysRevD.84.071103