Measurement of the Double-Differential Muon-neutrino Charged-Current Inclusive Cross Section in the NOvA Near Detector

TL;DR

This paper presents detailed measurements of muon-neutrino charged-current interactions in the NOvA near detector, revealing discrepancies with existing models especially at forward angles and low Q^2, highlighting the need for improved theoretical descriptions.

Contribution

First measurements of double-differential muon-neutrino charged-current cross sections in the NOvA near detector, providing critical data to test and refine neutrino interaction models.

Findings

Discrepancies observed at forward muon angles and low Q^2.

Current models underestimate the cross section in certain kinematic regions.

Data suggests missing suppression mechanisms in existing neutrino-nucleus scattering models.

Abstract

We report cross-section measurements of the final-state muon kinematics for \numu charged-current interactions in the NOvA near detector using an accumulated 8.09$\times10^{20}$ protons-on-target (POT) 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.