Quark Orbital-Angular-Momentum Distribution in the Nucleon

Abstract

We introduce gauge-invariant quark and gluon angular momentum distributions after making a generalization of the angular momentum density operators. From the quark angular momentum distribution, we define the gauge-invariant and leading-twist quark {\it orbital} angular momentum distribution $L_q(x)$. The latter can be extracted from data on the polarized and unpolarized quark distributions and the off-forward distribution $E(x)$ in the forward limit. We comment upon the evolution equations obeyed by this as well as other orbital distributions considered in the literature.

8 pages, latex, no figures, minor corrections made

References in corpus (4)

• Measurement of the Proton's Neutral Weak Magnetic Form Factor
• Lorentz Symmetry and the Internal Structure of the Nucleon
• Chiral Quark Model of Nucleon Spin-Flavor Structure with SU(3) and Axial-U(1) Breakings
• Evolution Equations for Higher Moments of Angular Momentum Distributions

Cited by in corpus (44)

• Generalized Parton Distributions
• Large-Momentum Effective Theory
• Viewing the Proton Through "Color"-Filters
• Proton Spin Structure from Measurable Parton Distributions
• Gluon orbital angular momentum at small-$x$
• Three-Quark Light-Cone Amplitudes of The Proton And Quark-Orbital-Motion Dependent Observables
• Leading Chiral Contributions to the Spin Structure of the Proton
• Angular Momentum Decomposition for an Electron
• The generalized parton distribution function (E^u+E^d)(x,xi,t) of the nucleon in the chiral quark soliton model
• Probing Parton Orbital Angular Momentum in Longitudinally Polarized Nucleon
• Helicity-dependent generalized parton distributions in constituent quark models
• Proton Spin Structure at Small-$x$
• Transverse Polarization of the Nucleon in Parton Picture
• Generalized form factors, generalized parton distributions and the spin contents of the nucleon
• The generalized parton distribution functions and the nucleon spin sum rules in the chiral quark soliton model
• The Parton Orbital Angular Momentum: Status and Prospects
• The relativistic center of mass in field theory with spin
• Justifying the Naive Partonic Sum Rule for Proton Spin
• Implications of Color Gauge Symmetry For Nucleon Spin Structure
• $\rho$ meson unpolarized generalized parton distributions with a light-front constituent quark model
• Counting Form Factors of Twist-Two Operators
• Gravitational form factors of $\rho$ meson with a light-cone constituent quark model
• Phenomenological analysis of the nucleon spin contents and their scale dependence
• Quark Orbital Angular Momentum in the Wandzura-Wilczek Approximation
• Gluon Spin, Canonical Momentum, and Gauge Symmetry
• More on the relation between the two physically inequivalent decompositions of the nucleon spin and momentum
• Chiral-odd generalized parton distributions, transversity decomposition of angular momentum, and tensor charges of the nucleon
• Spin Decomposition of Electron in QED
• Relativistic spin sum rules and the role of the pivot
• Counting and Tensorial Properties of Twist-Two Helicity-Flip Nucleon Form Factors
• Generalized Parton Distributions in Full Lattice QCD
• Generalized Parton Distributions and the Spin Structure of the Nucleon
• Transverse spin sum rule of the proton
• QCD evolution of the orbital angular momentum of quarks and gluons: Genuine twist-three part
• Moments of generalized parton distribution functions and the nucleon spin contents
• Proton spin after 30 years: what we know and what we don't?
• Orbital structure of quarks inside the nucleon in the light-cone diquark model
• Are there infinitely many decompositions of the nucleon spin ?
• Orbital Angular Momentum Parton Distributions in Light-Front Dynamics
• Nucleon-Quarkonium Elastic Scattering and the Gluon Contribution to Nucleon Spin
• Quark and gluon orbital angular momentum: Where are we?
• Contribution of Orbital Angular Momentum to the Nucleon Spin
• Operator product expansion coefficient functions in terms of composite operators only. Nonsinglet case
• OPE coefficient functions in terms of composite operators only. Singlet case