# From inclusive to semi-inclusive one-nucleon knockout in neutrino event generators

## TL;DR

This paper compares the semi-inclusive nucleon knockout modeling in neutrino event generators, specifically GENIE's approach versus a more accurate RDWIA calculation, revealing significant discrepancies that question current assumptions.

## Contribution

It introduces a comparison between GENIE's semi-inclusive modeling and a fully unfactorized RDWIA calculation, highlighting inaccuracies in the former.

## Key findings

- GENIE's approach differs significantly from RDWIA in nucleon kinematics.
- GENIE's assumptions may lead to unrealistic semi-inclusive cross section predictions.
- The study emphasizes the need for improved modeling in neutrino event generators.

## Abstract

In neutrino event generators, for models for neutrino and electron scattering only inclusive cross sections are implemented. When these models are used to describe a semi-inclusive cross section, the event generator attaches the hadron variables based on some assumptions. In this work we compare the nucleon kinematics given by the method used in the GENIE event generator, e.g. in the implementation of the SuSAv2 model, to a fully unfactorized calculation using the relativistic distorted wave impulse approximation (RDWIA). We focus on kinematics relevant to the $e4\nu$ analysis and show that observables obtained with RDWIA differ significantly from those of the approximate method used in GENIE, the latter should be considered unrealistic.