Spin structure in non-forward partons

Abstract

Renormalisation induces anomalous contributions in light-cone correlation functions. We discuss the role of the axial anomaly and gluon topology in non-forward parton distributions noting that non-forward matrix elements of the gluonic Chern-Simons current K_μ are not gauge-invariant even in perturbation theory. The axial anomaly means that one has to be careful how to interpret information from hard exclusive reactions about the orbital angular-momentum carried by the proton's internal constituents.

15 pages

References in corpus (5)

• Light-Cone Wavefunction Representation of Deeply Virtual Compton Scattering
• The Gauge-Invariant Angular Momentum Sum-Rule for the Proton
• The Spin Structure of the Proton and Polarized Collider Physics
• Review of recent results in spin physics
• The Angular Momentum and g_1^p Sum Rules for the Proton

Cited by in corpus (5)

• Generalized Parton Distributions
• Quark Imaging in the Proton Via Quantum Phase-Space Distributions
• The Spin Structure of the Proton
• The nucleon's octet axial-charge g_A^8 with chiral corrections
• Chiral and trace anomalies in Deeply Virtual Compton Scattering II: QCD factorization and beyond