Influence of the N*(1440) and N*(1535) Resonances in Intermediate Energy pp and np Scattering

TL;DR

This paper examines how including the N*(1440) and N*(1535) resonances affects the modeling of proton-proton and neutron-proton scattering data at energies up to 1.5 GeV, enhancing understanding of nucleon-nucleon interactions.

Contribution

It introduces the incorporation of two low-lying N* resonances into NN interaction models to better describe scattering data above the pion production threshold.

Findings

Resonance inclusion improves fit to scattering observables.

N*(1440) and N*(1535) significantly influence intermediate energy scattering.

Enhanced model accuracy for energies up to 1.5 GeV.

Abstract

Motivated by a recent measurement of proton-proton elastic scattering observables up to 3.0 GeV, we investigate the description of those data within models of the nucleon-nucleon (NN) interaction valid above the pion production threshold. In addition to including the well known Delta resonance we incorporate two low-lying N* resonances, the N*(1440) and the N*(1535), and study their influence on pp and np observables for projectile laboratory kinetic energies up to 1.5 GeV.