Notes on the orbital angular momentum of quarks in the nucleon
arXiv:1111.3547 · doi:10.1016/j.physletb.2012.01.024
Abstract
We discuss the orbital angular momentum of partons inside a longitudinally polarized proton in the recently proposed framework of spin decomposition. The quark orbital angular momentum defined by Ji can be decomposed into the `canonical' and the `potential' angular momentum parts, both of which are represented as the matrix element of a manifestly gauge invariant operator.
11 pages; v2. added comments and references on the Wigner distribution approach; v3. improved presentation, to appear in Phys.Lett.B