Orbital angular momenta of quarks and gluons in the nucleon -model-dependent versus model-independent extractions-

Journal Article · Wed Dec 14 00:00:00 EST 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3667301· OSTI ID:22004001

Wakamatsu, Masashi ^[1]

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1. Department of Physics, Faculty of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

We demonstrate that there exist two kinds of gauge-invariant decompositions of the nucleon spin, which are physically inequivalent. The quark and gluon orbital angular momenta (OAMs) appearing in one decomposition are basically the canonical OAMs, while the quark and gluon OAMs appearing in another decomposition are called the dynamical OAMs. It is shown that the dynamical OAMs of quarks and gluons in the nucleon can be related to definite high-energy deep-inelastic-scattering observables. On the other hand, we conjecture that the canonical OAMs of quarks and gluon in the nucleon are model-dependent quantities, which is meaningful only within a specific theoretical model of the nucleon.

• OSTI ID: 22004001
• Journal Information: AIP Conference Proceedings, Vol. 1418, Issue 1; Conference: PacSPIN2011: 8. Circum-Pan-Pacific symposium on high energy spin physics, Cairns, QLD (Australia), 20-24 Jun 2011; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
DEEP INELASTIC SCATTERING
GAUGE INVARIANCE
GLUONS
MAGNETIC MOMENTS
NUCLEONS
ORBITAL ANGULAR MOMENTUM
PARTICLE STRUCTURE
POLARIZATION
PROBABILITY
QUARKS
SPIN