Quark orbital angular momentum in a light-cone representation

1998/08/02 by Bo-Qiang Ma, Iván Schmidt, Ivan Schmidt · 46 citations
Physics and Astronomy · #Angular momentum #Angular momentum coupling #Helicity #Particle physics #Particle physics theoretical and experimental studies #Physics #Pulsars and Gravitational Waves Research #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Quark #Quark model #Quarkonium #Total angular momentum quantum number #hep-ex #hep-ph #nucl-th

paper · pdf · doi:10.1103/physrevd.58.096008

published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 58(9) (American Physical Society) · 20 latex pages, including an eps figure, to appear in Phys. Rev. D

arxiv created 1998/08/02 · openalex publication_date 1998/10/05 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We perform an analysis of the quark angular momentum in a light-cone representation by taking into account the effect due to the Melosh-Wigner rotation and find that there is a relativistic correction factor connecting the quark orbital angular momentum with the quark model spin distribution: L_q(x)=〈M_L(x)〉\ensuremathΔq_QM(x). The quark orbital angular momentum L_q(x) and the quark helicity distribution \ensuremathΔq(x) are connected to the quark model spin distribution \ensuremathΔq_QM(x) by a relation (1)/(2)\ensuremathΔq(x)+L_q(x)=(1)/(2)\ensuremathΔq_QM(x), which means that one can decompose the quark model spin contribution \ensuremathΔq_QM(x) by a quark helicity term \ensuremathΔq(x) plus an orbital angular momentum term L_q(x). There is also a new relation connecting the quark orbital angular momentum with the measurable quark helicity distribution and transversity distribution (\ensuremathδq(x)): \ensuremathΔq(x)+L_q(x)=\ensuremathδq(x), from which we may have new sum rules connecting the quark orbital angular momentum with the nucleon axial and tensor charges.

Citations

• Determination of αs and the nucleon spin decomposition using recent polarized structure function data
• Wavefunction-independent relations between the nucleon axial-coupling gA and the nucleon magnetic moments
• Melosh rotation: source of the proton's missing spin
• Tensor charge of the nucleon in lattice QCD
• Magnetic moments of the baryon decuplet in a relativistic quark model
• Quantum chromodynamics and other field theories on the light cone
• On Unitary Representations of the Inhomogeneous Lorentz Group
• Proton spin structure in the rest frame
• Probing nucleon spin structure
• Sum Rule for High-Energy Electron-Proton Scattering
• Relativistic corrections to the electromagnetic and axial moments of nuclei and other composite systems
• Measurement of the spin-dependent structure function g1(x) of the proton