Current status of final-state interaction models and their impact on neutrino-nucleus interactions

Abstract

Hadrons produced in neutrino-nucleus interactions may re-scatter while propagating through the nuclear medium. Such re-scatters, often called Final State Interactions (FSI), can change the charge and multiplicity of the outgoing hadrons, as well as altering their final state kinematics. A good description of these processes is crucial for accurate measurements of the neutrino energy spectra - a key part of neutrino oscillation analyses. We present the comparison of predictions from various neutrino interaction event generators (NEUT, GENIE, Geant4, NuWro and FLUKA) with thin-target pion/nucleon scattering data. The FSI model used in NEUT is a microscopic cascade where the hadrons are propagated semiclassically through a nuclear medium in finite steps. A new tune of the cascade model has been performed for improvements from the current NEUT parameters using external data, and is presented.