We study neutrino-induced charged-current (CC) ${\pi }^0$ production on carbon nuclei using events with fully imaged final-state proton-${\pi }^0$ systems. Novel use of final-state correlations based on transverse kinematic imbalance enables the first measurements of the struck nucleon’s Fermi motion, of the intranuclear momentum transfer (IMT) dynamics, and of the final-state hadronic momentum configuration in neutrino pion production. Event distributions are presented for (i) the momenta of neutrino-struck neutrons below the Fermi surface, (ii) the direction of missing transverse momentum characterizing the strength of IMT, and (iii) proton-pion momentum imbalance with respect to the lepton scattering plane. The observed Fermi motion and IMT strength are compared to the previous $\mathrm{MINER}\nu \mathrm{A}$ measurement of neutrino CC quasielastic-like production. The measured shapes and absolute rates of these distributions, as well as the cross section asymmetries, show tensions with predictions from current neutrino generator models.

• Received 13 February 2020
• Accepted 28 September 2020
• Corrected 11 December 2020

DOI:https://doi.org/10.1103/PhysRevD.102.072007

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Published by the American Physical Society