First measurement of muon-neutrino disappearance in NOvA

Abstract

This paper reports the first measurement using the NOvA detectors of ${\nu }_{\mu }$ disappearance in a ${\nu }_{\mu }$ beam. The analysis uses a 14 kton-equivalent exposure of $2.74\times 10^{20}$ protons-on-target from the Fermilab NuMI beam. Assuming the normal neutrino mass hierarchy, we measure $\Delta m_{32}^2=(2.52_{-0.18}^{+0.20})\times 10^{-3}$ eV${}^2$ and ${\sin }^2{\theta }_{23}$ in the range 0.38-0.65, both at the 68% confidence level, with two statistically-degenerate best fit points at ${\sin }^2{\theta }_{23}=$ 0.43 and 0.60. Results for the inverted mass hierarchy are also presented.

8 pages, 6 figures. Submitted to Phys. Rev. D Rapid Communications