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arXiv · hep-ph/9808305

Implications of Color Gauge Symmetry For Nucleon Spin Structure

Pervez Hoodbhoy·Xiangdong Ji·Wei Lu
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Abstract

We study the chromodynamical gauge symmetry in relation to the internal spin structure of the nucleon. We show that 1) even in the helicity eigenstates the gauge-dependent spin and orbital angular momentum operators do not have gauge-independent matrix element; 2) the evolution equations for the gluon spin take very different forms in the Feynman and axial gauges, but yield the same leading behavior in the asymptotic limit; 3) the complete evolution of the gauge-dependent orbital angular momenta appears intractable in the light-cone gauge. We define a new gluon orbital angular momentum distribution $L_g(x)$ which {\it is} an experimental observable and has a simple scale evolution. However, its physical interpretation makes sense only in the light-cone gauge just like the gluon helicity distribution $Δg(x)$y.

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Pervez Hoodbhoy, Xiangdong Ji, Wei Lu. 1998-09-03. Implications of Color Gauge Symmetry For Nucleon Spin Structure. https://doi.org/10.1103/physrevd.59.074010

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