Nucleon spin decomposition with one dynamical gluon

TL;DR

This paper develops light-front wave functions for the nucleon using an effective QCD Hamiltonian, incorporating a dynamical gluon to analyze its impact on the nucleon's spin structure and parton distributions.

Contribution

It introduces a novel approach to include a dynamical gluon in nucleon wave functions within light-front QCD, advancing understanding of nucleon spin decomposition.

Findings

Dynamical gluon significantly affects gluon densities.

Inclusion of gluon improves description of quark distribution functions.

Results align with QCD scale evolution expectations.

Abstract

We solve for the light-front wave functions of the nucleon from a light-front quantum chromodynamics (QCD) effective Hamiltonian with three-dimensional confinement. We obtain solutions using constituent three quarks combined with three quarks and one gluon Fock components. The resulting light-front wave functions provide a good quality description of the nucleon's quark distribution functions following QCD scale evolution. We present the effects from incorporating a dynamical gluon on the nucleon's gluon densities, helicity distribution and orbital angular momentum that constitutes the nucleon spin sum rule.