The pion-cloud contribution to the electromagnetic nucleon structure

TL;DR

This paper investigates how pionic effects influence the electromagnetic structure of the nucleon using a hybrid constituent-quark model within relativistic quantum mechanics, highlighting significant effects at low momentum transfer.

Contribution

It introduces a hybrid quark model including pionic components to study nucleon form factors, extending previous relativistic quantum mechanics approaches.

Findings

Pionic effects are significant below Q^2 ≈ 0.5 GeV^2.

The model produces reasonable nucleon form factor results.

Pionic contributions are less important at higher Q^2.

Abstract

The present contribution continues and extends foregoing work on the calculation of electroweak form factors of hadrons using the point-form of relativistic quantum mechanics. Here we are particularly interested in studying pionic effects on the electromagnetic structure of the nucleon. To this aim we employ a hybrid constituent-quark model that comprises, in addition to the $3q$ valence component, also a $3q$+$\pi$ non-valence component. With a simple wave function for the $3q$ component we get reasonable results for the nucleon form factors. In accordance with other authors we find that the pionic effect is significant only below $Q^2\lesssim 0.5$~GeV$^2$.