Implications of color gauge symmetry for nucleon spin structure

Journal Article · Thu Apr 01 04:00:00 EST 1999 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.59.074010· OSTI ID:322027

Hoodbhoy, P; Ji, X; Lu, W ^[1]

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1. Department of Physics, University of Maryland, College Park, Maryland 20742 (United States)

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, and (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{sub g}(x) which {ital 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 {Delta}g(x). thinsp {copyright} {ital 1999} {ital The American Physical Society}

• OSTI ID: 322027
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 7 Vol. 59; ISSN 0556-2821; ISSN PRVDAQ
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ANGULAR MOMENTUM
COLOR MODEL
GAUGE INVARIANCE
GLUONS
HELICITY
NUCLEONS
QUANTUM CHROMODYNAMICS
SPIN