MK single pion production model

TL;DR

This paper updates the MK model for neutrino-induced single pion production by redefining helicity amplitudes and form factors, fitted to electron scattering data, enhancing its accuracy and reliability.

Contribution

The paper introduces a revised MK model with new helicity amplitudes and vector-current form factors, fitted to experimental data, improving the description of neutrino-nucleon interactions.

Findings

Updated helicity amplitudes for resonance regions

New vector-current form factors fitted to data

Enhanced model accuracy for single pion production

Abstract

This paper presents an update to the MK model, which was developed to describe single pion production in neutrino-nucleon interactions. Originally the MK model used the helicity amplitudes and the hadronic current form-factors of the Rein and Sehgal model. The update includes a new definition for the helicity amplitudes in the first and second resonance regions, and new vector-current form factors. Fits to electron-proton scattering data were used to determine these vector-current form factors, and to assign errors to the constrained free parameters of the model.