Quark spin and momentum distributions of the nucleon

Journal Article · Thu Jun 01 04:00:00 EDT 1989 · Phys. Rev. D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.39.3257· OSTI ID:6139956

Dziembowski, Z; Weber, H J; Mankiewicz, L; Szczepaniak, A

We analyze the recent European Muon Collaboration (EMC) data on the proton spin asymmetry in a relativistic constituent-quark model of the nucleon. In a convolution approach we calculate the /ital x/ dependence of the spin-weighted and spin-averaged quark distributions. We estimate the size of orbital angular momentum carried by the valence constituents, , to be sizable (about 20--25 % of the proton spin). This depletes the valence-quark contribution to the proton spin, but not enough to account for the spin deficit claimed by the EMC.

• Research Organization: Institute of Nuclear and Particle Physics, University of Virginia, Charlottesville, Virginia 22901(US); Nicolaus Copernicus Astronomical Centre of the Polish Academy of Sciences, Warsaw, Poland; Institute of Theoretical Physics, Warsaw University, Warsaw, Poland
• OSTI ID: 6139956
• Journal Information: Phys. Rev. D; (United States), Journal Name: Phys. Rev. D; (United States) Vol. 39:11; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

645204* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Strong Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANGULAR MOMENTUM
ASYMMETRY
BARYONS
COMPOSITE MODELS
ELEMENTARY PARTICLES
EMC EFFECT
EQUATIONS
FERMIONS
FIELD THEORIES
FUNCTIONS
GENERAL RELATIVITY THEORY
GLUONS
HADRONS
INTERACTIONS
LIGHT CONE
MATHEMATICAL MODELS
NUCLEONS
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PROPERTIES
PARTON MODEL
POLARIZATION
POSTULATED PARTICLES
PROTONS
QUARK MODEL
RELATIVITY THEORY
SPACE-TIME
SPIN
STRUCTURE FUNCTIONS
SUM RULES
VALENCE