Probing nuclear effects with neutrino-induced charged-current neutral pion production
D. Coplowe, O. Altinok, Z. Ahmad Dar, F. Akbar, D. A. Andrade, G. Barr, A. Bashyal, A. Bercellie, M. Betancourt, A. Bodek, A. Bravar, H. S. Budd, G. Cáceres, T. Cai, M. F. Carneiro, H. da Motta, S. Dytman, G. A. Díaz, J. Félix, L. Fields, A. Filkins, R. Fine, A. M. Gago, H. Gallagher, A. Ghosh, R. Gran, D. A. Harris, S. Henry, S. Jena, J. Kleykamp, M. Kordosky, D. Last, T. Le, A. Lozano, X.-G. Lu, E. Maher, S. Manly, W. A. Mann, C. Mauger, K. S. McFarland, B. Messerly, J. Miller, J. G. Morfín, D. Naples, J. K. Nelson, C. Nguyen, A. Norrick, A. Olivier, V. Paolone, Gabriel Perdue, M. A. Ramírez, R. D. Ransome, H. Ray, P. A. Rodrigues, D. Ruterbories, H. Schellman, J. T. Sobczyk, C. J. Solano Salinas, Hang Su, M. Sultana, V. S. Syrotenko, E. Valencia, D. Wark, A. Weber, M. Wospakrik, C. Wret, B. Yaeggy, L. Zazueta
Abstract
We study neutrino-induced charged-current (CC) ${\ensuremath{\pi}}^{0}$ production on carbon nuclei using events with fully imaged final-state proton-${\ensuremath{\pi}}^{0}$ 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 $\mathrm{MINER}\ensuremath{\nu}\mathrm{A}$ 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.