Impact of final state interactions on neutrino-nucleon pion production cross sections extracted from neutrino-deuteron reaction data

Abstract

The current and near-future neutrino-oscillation experiments require significantly improved neutrino-nucleus reaction models. Neutrino-nucleon pion production data play a crucial role to validate corresponding elementary amplitudes that go into such neutrino-nucleus models. Thus, the currently available data extracted from charged-current neutrino-deuteron reaction data (νμd→μ-πNN) must be corrected for nuclear effects such as the Fermi motion and final state interactions (FSI). We study νμd→μ-πNN with a theoretical model including the impulse mechanism supplemented by FSI from NN and πN rescatterings. An analysis of the spectator momentum distributions reveals that the FSI effects significantly reduce the spectra over the quasifree peak region and leads to a useful recipe to extract information of elementary νμN→μ-πN processes using νμd→μ-πNN data, with the important FSI corrections taken into account. We provide νμN→μ-πN total cross sections by correcting the deuterium bubble chamber data for the FSI and Fermi motion. The results will bring a significant improvement on neutrino-nucleus reaction models for the near-future neutrino-oscillation experiments.