Speaker
Description
The precise determination of neutrino properties in current and future accelerator-based oscillation experiments requires a good understanding and realistic modeling of neutrino interactions in the detectors: it is crucial to distinguish signal from background, reconstruct the neutrino energy and minimize systematic uncertainties. A significant fraction of the inelastic-scattering neutrino-nucleon cross section comes from the excitation of baryonic resonances. Pion production mediated by $\Delta(1232)$ excitation is the most important inelastic process. Nonetheless, at current (NOvA) and future (DUNE) oscillation experiments, with neutrino fluxes in the few-GeV region, heavier baryonic excited states become important, leading to a variety of reaction channels such as multiple-pion, eta or strangeness production. The theoretical description of baryon resonance excitation, and meson production in general, currently relies on the input from their electromagnetic counterparts for the vector part of the interaction, while pion-nucleon scattering constrains the axial current at $Q^2 = 0$ thanks to PCAC. The $Q^2$ dependence of the axial current remains poorly known. Although the MINERvA experiment recently obtained valuable data on neutrino-induced pion production, final state interactions in the nuclear target ($^{12}$C) hinder the extraction of reliable information about the elementary process, so that new measurements on hydrogen and deuterium are needed.
