Justifying the naive partonic sum rule for proton spin

We provide a theoretical basis for understanding the spin structure of the proton in terms of the spin and orbital angular momenta of free quarks and gluons in Feynman's parton picture. We show that each term in the Jaffe–Manohar spin sum rule can be related to the matrix element of a gauge-inv...

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Bibliographic Details
Main Authors: Xiangdong Ji, Jian-Hui Zhang, Yong Zhao
Format: Article
Language:English
Published: Elsevier 2015-04-01
Series:Physics Letters B
Online Access:http://www.sciencedirect.com/science/article/pii/S0370269315001458