Measurement of the double-differential muon-neutrino charged-current inclusive cross section in the NOvA near detector

We report cross-section measurements of the final-state muon kinematics for ${\nu }_{\mu }$ charged-current interactions in the NOvA near detector using an accumulated $8.09×{10}^{20}$ protons on target in the NuMI beam. We present the results as a double-differential cross section in the observed outgoing muon energy and angle, as well as single-differential cross sections in the derived neutrino energy, ${E}_{\nu }$, and square of the four-momentum transfer, ${Q}^{2}$. We compare the results to inclusive cross-section predictions from various neutrino event generators via ${\chi }^{2}$ calculations using a covariance matrix that accounts for bin-to-bin correlations of systematic uncertainties. These comparisons show a clear discrepancy between the data and each of the tested predictions at forward muon angle and low ${Q}^{2}$, indicating a missing suppression of the cross section in current neutrino-nucleus scattering models.