1/[ital N][sub [ital c]] expansion for baryons

Journal Article · Sun May 01 00:00:00 EDT 1994 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.49.4713· OSTI ID:5010824

Dashen, R; Jenkins, E; Manohar, A V ^[1]

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1. Department of Physics, University of California at San Diego, La Jolla, California 92093 (United States)

A systematic expansion in 1/[ital N][sub [ital c]] is constructed for baryons in QCD. Predictions of the 1/[ital N][sub [ital c]] expansion at leading and subleading order for baryon axial vector current coupling constant ratios such as [ital F]/[ital D], baryon masses, and magnetic moments are derived. The baryon sector of QCD has a light quark spin-flavor symmetry at leading order in 1/[ital N][sub [ital c]]. The formalism of induced representations for contracted Lie algebras is introduced to explain the consequences of this symmetry. Relations are first derived for the case of two quark flavors. The generalization of the large [ital N][sub [ital c]] expansion to three flavors is subtle and is treated using several complementary methods. The 1/[ital N][sub [ital c]] expansion severely restricts the form of SU(3) breaking in the baryon sector. Extrapolation of the large [ital N][sub [ital c]] results to [ital N][sub [ital c]]=3 permits a quantitative comparison with experimental data. Deviations of the measured quantities from exact spin-flavor symmetry predictions are accurately described by the subleading 1/[ital N][sub [ital c]] corrections. Implications of the 1/[ital N][sub [ital c]] expansion for baryon chiral perturbation theory are discussed.

• DOE Contract Number: FG03-90ER40546
• OSTI ID: 5010824
• Journal Information: Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 49:9; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

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72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ALGEBRAIC CURRENTS
AXIAL-VECTOR CURRENTS
BARYONS
COLOR MODEL
COMPOSITE MODELS
COUPLING CONSTANTS
CURRENTS
ELEMENTARY PARTICLES
EXPANSION
EXTRAPOLATION
FERMIONS
FIELD THEORIES
HADRONS
LIE GROUPS
MAGNETIC MOMENTS
MASS
MATHEMATICAL MODELS
NUMERICAL SOLUTION
PARTICLE MODELS
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
QUARK MODEL
SYMMETRY
SYMMETRY GROUPS