Gluon polarization in the nucleon demystified

Abstract

Recently, X. Chen et al. proposed a new approach to the gauge invariant decomposition of the nucleon spin into helicity and orbital parts. The key ingredient in their construction is the separation of the gauge field into `physical' and `pure gauge' parts. We suggest a simple separation scheme and show that the resulting gluon helicity coincides with the first moment of the conventional polarized gluon distribution measurable in high energy experiments.

6 pages

References in corpus (8)

• Spin and orbital angular momentum in gauge theories: Nucleon spin structure and multipole radiation revisited
• Reply to the Comment on "Spin and orbital angular momentum in gauge theories: Nucleon spin structure and multipole radiation revisited" [PRL 100:232002 (2008)]
• On Gauge-Invariant Decomposition of Nucleon Spin
• Do gluons carry half of the nucleon momentum?
• Gauge- and frame-independent decomposition of nucleon spin
• Proper identification of the gluon spin
• Nucleon Spin in QCD: Old Crisis and New Resolution
• Spin Physics: Session Summary

Cited by in corpus (48)

• Notes on the orbital angular momentum of quarks in the nucleon
• Spin Hydrodynamics and Symmetric Energy-Momentum Tensors -- A current induced by the spin vorticity --
• The Spin Structure of the Nucleon
• Gluon orbital angular momentum at small-$x$
• Is gauge-invariant complete decomposition of the nucleon spin possible ?
• Inclusive double-helicity asymmetries in neutral pion and eta meson production in $\vec{p}+\vec{p}$ collisions at $\sqrt{s}=200$ GeV
• Glue spin and helicity in proton from lattice QCD
• A Lattice Study of Quark and Glue Momenta and Angular Momenta in the Nucleon
• Parton Orbital Angular Momentum and Final State Interactions
• Wilson lines and orbital angular momentum
• Geometrical approach to the proton spin decomposition
• Physics of Gluon Helicity Contribution to Proton Spin
• Gluon Helicity Delta G from a Universality Class of Operators on a Lattice
• The light-front gauge-invariant energy-momentum tensor
• The Parton Orbital Angular Momentum: Status and Prospects
• Quark tensor charge and electric dipole moment within the Schwinger-Dyson formalism
• Gluon Spin, Canonical Momentum, and Gauge Symmetry
• More on the relation between the two physically inequivalent decompositions of the nucleon spin and momentum
• Quark scalar, axial, and pseudoscalar charges in the Schwinger-Dyson formalism
• On gauge invariant nucleon spin decomposition
• Orbital Angular Momentum and Generalized Transverse Momentum Distribution
• Gauge symmetry and background independence: Should the proton spin decomposition be path independent?
• Inclusive Single-Spin Asymmetries, Quark-Photon, and Quark-Quark Correlations
• Transverse Force on Quarks in DIS
• Physical symmetries and gauge choices in the Landau problem
• Gauge Invariant Descriptions of Gluon Polarizations
• Gravitational transverse-momentum distributions
• Unravelling the physical meaning of the Jaffe-Manohar decomposition of the nucleon spin
• Measurements of double-helicity asymmetries in inclusive $J/\psi$ production in longitudinally polarized $p+p$ collisions at $\sqrt{s}=510$ GeV
• Relativistic decomposition of the orbital and the spin angular momentum in chiral physics and Feynman's angular momentum paradox
• On the two remaning issues in the gauge-invariant decomposition problem of the nucleon spin
• Proton spin after 30 years: what we know and what we don't?
• Are there infinitely many decompositions of the nucleon spin ?
• A still unsettled issue in the nucleon spin decomposition problem : On the role of surface terms and gluon topology
• Quark and Glue Components of the Proton Spin from Lattice Calculation
• Gauge Invariant Descriptions of Gluon Polarizations Revisited
• Double longitudinal-spin asymmetries in $J/\psi$ production at RHIC
• On the decomposition theorem for gluons
• The contour gauge in use: telling untold
• Pseudogauge ambiguity in the distributions of energy density, pressure, and shear force inside the nucleon
• The proton spin decomposition : path dependence and gauge symmetry
• Gauge invariant gluon spin operator for spinless non-linear wave solutions
• Scaling Transformation for Nonlocal Interactions
• The gauge-invariant canonical energy-momentum tensor
• Energy-momentum tensor form factors and spin density distribution in the nucleon calculated in a quantized Skyrme model with vector mesons
• Nucleon spin decomposition at twist three
• Role of higher twist distributions in the tomography of proton
• The nucleon spin decomposition: news and experimental implications