# Quark orbital angular momentum from Wigner distributions and light-cone wave functions

Abstract : We investigate the quark orbital angular momentum of the nucleon in the absence of gauge-field degrees of freedom, by using the concept of the Wigner distribution and the light-cone wave functions of the Fock-state expansion of the nucleon. The quark orbital angular momentum is obtained from the phase-space average of the orbital angular momentum operator weighted with the Wigner distribution of unpolarized quarks in a longitudinally polarized nucleon. We also derive the light-cone wave-function representation of the orbital angular momentum. In particular, we perform an expansion in the nucleon Fock-state space and decompose the orbital angular momentum into the N-parton state contributions. Explicit expressions are presented in terms of the light-cone wave functions of the three-quark Fock state. Numerical results for the up and down quark orbital angular momenta of the proton are shown in the light-cone constituent quark model and the light-cone chiral quark-soliton model.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-00713743
Contributor : Sophie Heurteau <>
Submitted on : Monday, July 2, 2012 - 3:10:41 PM
Last modification on : Wednesday, September 16, 2020 - 4:07:54 PM

### Citation

C. Lorcé, B. Pasquini, X. Xiong, F. Yuan. Quark orbital angular momentum from Wigner distributions and light-cone wave functions. Physical Review D, American Physical Society, 2012, 85, pp.114006. ⟨10.1103/PhysRevD.85.114006⟩. ⟨in2p3-00713743⟩

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