scholarly journals Lorentz invariance and QCD equation of motion relations for generalized parton distributions and the dynamical origin of proton orbital angular momentum

2018 ◽  
Vol 98 (7) ◽  
Author(s):  
Abha Rajan ◽  
Michael Engelhardt ◽  
Simonetta Liuti
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Lorentz Invariance ◽  
Equation Of Motion ◽  
Parton Distributions ◽  
Generalized Parton Distributions ◽  
Dynamical Origin ◽  
Proton Orbital

QUARK ORBITAL ANGULAR MOMENTUM AND GENERALIZED PARTON DISTRIBUTIONS

2003 ◽  
Vol 18 (08) ◽  
pp. 1303-1309 ◽  
Author(s):  
XIANGDONG JI
Keyword(s):  
Angular Momentum ◽  
Quantum Chromodynamics ◽  
Orbital Angular Momentum ◽  
Parton Distributions ◽  
Generalized Parton Distributions ◽  
Quark Orbital Angular Momentum

In this talk, I review the merit of introducing and measuring the quark orbital angular momentum contribution to the spin of the nucleon in the context of quantum chromodynamics.

GPDs AND TMDs

2012 ◽  
Vol 20 ◽  
pp. 75-83
Author(s):  
MATTHIAS BURKARDT
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Transverse Plane ◽  
Final State ◽  
Parton Distributions ◽  
Generalized Parton Distributions ◽  
Wigner Distributions ◽  
Quark Orbital Angular Momentum ◽  
Final State Interactions ◽  
The Difference

For transversely polarized nucleons the distribution of quarks in the transverse plane is transversely shifted and that shift can be described in terms of Generalized Parton Distributions (GPDs). This observation provides a 'partonic' derivation of the Ji-relation for the quark angular momentum in terms of GPDs. Wigner distributions are used to show that the difference between the Jaffe-Manohar definiton of quark orbital angular momentum and that of Ji is equal to the change of orbital angular momentum due to the final state interactions as the struck quark leaves the target in a DIS experiment.

scholarly journals WIGNER DISTRIBUTIONS AND QUARK ORBITAL ANGULAR MOMENTUM

2012 ◽  
Vol 20 ◽  
pp. 84-91 ◽  
Author(s):  
CÉDRIC LORCÉ ◽  
BARBARA PASQUINI
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Constituent Quark ◽  
Constituent Quark Model ◽  
Parton Distributions ◽  
Transverse Momentum Dependent ◽  
Generalized Parton Distributions ◽  
Wigner Distributions ◽  
Quark Orbital Angular Momentum ◽  
Quark Phase

We discuss the quark phase-space or Wigner distributions of the nucleon which combine in a single picture all the information contained in the generalized parton distributions and the transverse-momentum dependent parton distributions. In particular, we present results for the distribution of unpolarized quarks in a longitudinally polarized nucleon obtained in a light-front constituent quark model. We show how the quark orbital angular momentum can be extracted from the Wigner distributions and compare it with alternative definitions.

scholarly journals SPIN AND OTHER ASPECTS OF GENERALIZED PARTON DISTRIBUTIONS

2003 ◽  
Vol 18 (08) ◽  
pp. 1319-1326
Author(s):  
MARKUS DIEHL
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Parton Distribution ◽  
Bound States ◽  
Quantum Mechanical ◽  
Longitudinal Structure ◽  
Parton Distributions ◽  
Generalized Parton Distributions ◽  
Mechanical Interference ◽  
Higher Spin

I discuss how generalized parton distribution probe various aspects of QCD bound states. Topics include the interplay between transverse and longitudinal structure, quantum mechanical interference, orbital angular momentum, helicity flip, and higher-spin targets.

scholarly journals Wigner Distributions and Orbital Angular Momentum of Quarks

2015 ◽  
Vol 37 ◽  
pp. 1560040
Author(s):  
Asmita Mukherjee ◽  
Sreeraj Nair ◽  
Vikash Kumar Ojha
Keyword(s):  
Angular Momentum ◽  
Transverse Momentum ◽  
Model Calculation ◽  
Orbital Angular Momentum ◽  
Momentum Space ◽  
Recent Model ◽  
Parton Distributions ◽  
Transverse Momentum Dependent ◽  
Generalized Parton Distributions ◽  
Wigner Distributions

We present a recent model calculation of the Wigner distributions for the quarks and the orbital angular momentum carried by the quarks. These Wigner distributions contain combined position and momentum space information of the quark distributions and are related to both generalized parton distributions (GPDs) and transverse momentum dependent parton distributions (TMDs).

Generalized TMDs

2015 ◽  
Vol 37 ◽  
pp. 1560037 ◽  
Author(s):  
Koichi Kanazawa ◽  
Cedric Lorcé ◽  
Andreas Metz ◽  
Barbara Pasquini ◽  
Marc Schlegel
Keyword(s):  
Angular Momentum ◽  
Transverse Momentum ◽  
Perturbative Qcd ◽  
Orbital Angular Momentum ◽  
Close Relation ◽  
Parton Distributions ◽  
Transverse Momentum Dependent ◽  
Model Independent ◽  
Mere Existence

Generalized transverse-momentum dependent parton distributions (GTMDs) encode the most general parton structure of hadrons. In this contribution, which is largely based on a recent publication,1 we focus on two twist-2 GTMDs which are denoted by F1,4 and G1,1 in parts of the literature. As already shown previously, both GTMDs have a close relation to orbital angular momentum of partons inside a hadron. However, recently even the mere existence of F1,4 and G1,1 has been doubted. We explain why this claim does not hold. We support our model-independent considerations by calculating the GTMDs in two spectator models and in perturbative QCD. For the model results we also explicitly check the relation to the orbital angular momentum of partons inside hadrons.

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