Quark content of the nucleon in QCD: Perturbative and nonperturbative aspects

Journal Article · Sun Oct 01 00:00:00 EDT 1989 · Physical Review (Section) D: Particles and Fields; (USA)

DOI:https://doi.org/10.1103/PhysRevD.40.2305· OSTI ID:5460771

Stefanis, N G ^[1]

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1. Institut fur Theoretische Physik II, Ruhr-Universitat Bochum, D-4630 Bochum, Federal Republic of Germany (DE)

We elaborate on two proposed model distribution amplitudes for the nucleon, based on perturbative light-cone QCD supplemented by QCD sum rules. The novel nonperturbative features of these amplitudes are discussed in detail. Reasonable predictions for the Dirac form factor of the proton and the neutron are obtained, paying particular attention to the treatment of the effective coupling constant {alpha}{sub {ital s}}(Q{sup 2}) and the scale parameter {Lambda}{sub QCD}. In addition, the stability properties of the sum rules for the moments of these model distribution amplitudes are analyzed. The range of values of the parameters entering the sum rules is estimated. Relying on expectation values of longitudinal-momentum fractions instead of moments, a heuristic interpretation of the physical content of the model distribution amplitudes is attempted.

• OSTI ID: 5460771
• Journal Information: Physical Review (Section) D: Particles and Fields; (USA), Vol. 40:7; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
NUCLEONS
QUARK MODEL
QUANTUM CHROMODYNAMICS
PERTURBATION THEORY
BOUND STATE
COUPLING CONSTANTS
DIRAC EQUATION
FORM FACTORS
LIGHT CONE
PROBABILITY
RENORMALIZATION
SCATTERING AMPLITUDES
TRANSVERSE MOMENTUM
WAVE FUNCTIONS
AMPLITUDES
BARYONS
COMPOSITE MODELS
DIFFERENTIAL EQUATIONS
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
FIELD THEORIES
FUNCTIONS
HADRONS
LINEAR MOMENTUM
MATHEMATICAL MODELS
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLE MODELS
PARTICLE PROPERTIES
QUANTUM FIELD THEORY
SPACE-TIME
WAVE EQUATIONS
645400* - High Energy Physics- Field Theory
645204 - High Energy Physics- Particle Interactions & Properties-Theoretical- Strong Interactions & Properties