Measurement of $\nu_{\mu}$ charged-current single $\pi^{0}$ production on hydrocarbon in the few-GeV region using MINERvA

TL;DR

This paper measures muon neutrino charged-current single pi-zero production on hydrocarbon at energies around 3 GeV using MINERvA, providing detailed cross sections and comparing them to simulation models to identify discrepancies.

Contribution

It presents the first detailed differential cross sections for this process in the 1.5-20 GeV range and compares them with predictions, highlighting areas where models need improvement.

Findings

Data agree with simulations for pi-zero kinematic distributions.

Discrepancies observed at low and high muon angles and Q^2 values.

Supports current generator models of pion intranuclear scattering.

Abstract

The semi-exclusive channel $\nu_{\mu}+\textrm{CH}\rightarrow\mu^{-}\pi^{0}+\textrm{nucleon(s)}$ is analyzed using MINERvA exposed to the low-energy NuMI $\nu_{\mu}$ beam with spectral peak at $E_{\nu} \simeq 3$ GeV. Differential cross sections for muon momentum and production angle, $\pi^{0}$ kinetic energy and production angle, and for squared four-momentum transfer are reported, and the cross section $\sigma(E_{\nu})$ is obtained over the range 1.5 GeV $\leq E_{\nu} <$ 20 GeV. Results are compared to GENIE and NuWro predictions and to published MINERvA cross sections for $\nu_{\mu}\textrm{-CC}(\pi^{+})$ and $\bar{\nu}_{\mu}\textrm{-CC}(\pi^{0})$. Disagreements between data and simulation are observed at very low and relatively high values for muon angle and for $Q^2$ that may reflect shortfalls in modeling of interactions on carbon. For $\pi^{0}$ kinematic distributions however, the data are consistent with the simulation and provide support for generator treatments of pion intranuclear scattering. Using signal-event subsamples that have reconstructed protons as well as $\pi^{0}$ mesons, the $p\pi^{0}$ invariant mass distribution is obtained, and the decay polar and azimuthal angle distributions in the rest frame of the $p\pi^{0}$ system are measured in the region of $\Delta(1232)^+$ production, $W < 1.4$ GeV.