1995/09/30 by R. L. Jaffe · 3 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1016/0370-2693(95)01247-8
published as Phys.Lett.B365:359-366,1996 · 12 pages in REVTeX. The paper has been entirely revised
arxiv created 1995/11/07 · openalex publication_date 1996/01/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the operator description of the gluon spin contribution (Γ) to the nucleon's spin as it is measured in deep inelastic processes. Γ can be related to the forward matrix element of a local gluon operator in A+=0 gauge. In quark models the nucleon contains ambient color electric and magnetic fields. The latter are thought to be responsible for spin splittings among the light baryons. We show that these fields give rise to a significant \it negative\/ contribution to Γ at the quark model renormalization scale, μ02. The non-Abelian character of QCD is responsible for the sign of Γ. In a generic non-relativistic quark model ΓNQM=-8\over 9αNQM\over mq⟨1\over r⟩, in the bag model Γbag=-.1αbag. These correspond to ΓNQM≈ -0.7 and Γbag≈ -0.4 at αQCD≈ 1.0.