Evidence for the Absence of Gluon Orbital Angular Momentum in the Nucleon

Journal Article · Wed Aug 23 00:00:00 EDT 2006 · Submitted to Physics Letters B

DOI:https://doi.org/10.1016/j.physletb.2006.10.024· OSTI ID:890239

Brodsky, S J; Gardner, S

The Sivers mechanism for the single-spin asymmetry in unpolarized lepton scattering from a transversely polarized nucleon is driven by the orbital angular momentum carried by its quark and gluon constituents, combined with QCD final-state interactions. Both quark and gluon mechanisms can generate such a single-spin asymmetry, though only the quark mechanism can explain the small single-spin asymmetry measured by the COMPASS collaboration on the deuteron, suggesting the gluon mechanism is small relative to the quark mechanism. We detail empirical studies through which the gluon and quark orbital angular momentum contributions, quark-flavor by quark-flavor, can be elucidated.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 890239
• Report Number(s): SLAC-PUB-12062; hep-ph/0608219; TRN: US0604783
• Journal Information: Submitted to Physics Letters B, Journal Name: Submitted to Physics Letters B
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASYMMETRY
FINAL-STATE INTERACTIONS
GLUONS
LEPTONS
NUCLEONS
ORBITAL ANGULAR MOMENTUM
QUANTUM CHROMODYNAMICS
QUARKS
SCATTERING
Phenomenology-HEP
HEPPH
HEPTH