Smallness of gluon coupling to constituent quarks in baryons and validity of nonrelativistic quark model

Journal Article · Sun Nov 01 00:00:00 EST 1992 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.46.4068· OSTI ID:7158021

Morpurgo, G ^[1]

---

1. Istituto di Fisica dell'Universita and Istituto Nazionale di Fisica Nucleare, Genova (Italy)

A study of the parametrization of baryon masses and other quantities leads to a ratio {approx}1/5 for two-gluon-exchange versus one-gluon-exchange terms between two constituent quarks in a baryon. This fact (plus the factor 3 reduction from each additional order in flavor breaking) explains the success, to a part per thousand, of a new baryon mass formula (Phys. Rev. Lett. 68, 139 (1992)). It also explains why the results of SU(3) that neglect second-order flavor breaking (such as the Gell-Mann--Okubo baryon mass formula) work much better than expected. Finally the general parametrization, plus the above reduction factors, clarify why the naive'' nonrelativistic quark model (NRQM) is quantitatively fairly good. The reasons are twofold: (a) The structure of the general parametrization (an exact consequence of any QCD-like relativistic field theory) is similar to that of the NRQM; (b) the smallness of the gluon coupling and the reduction factor due to flavor imply that the additive (one-body) terms in the parametrization prevail on the two-body terms and the latter on the three-body ones, the typical feature of the naive'' NRQM.

• OSTI ID: 7158021
• Journal Information: Physical Review, D (Particles Fields); (United States), Vol. 46:9; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYONS
QUARK MODEL
MASS FORMULAE
CIM MODEL
COUPLING
FEYNMAN DIAGRAM
FLAVOR MODEL
GLUONS
MAGNETIC MOMENTS
MASS RENORMALIZATION
QUANTUM CHROMODYNAMICS
SPIN
ANGULAR MOMENTUM
BOSONS
COMPOSITE MODELS
DIAGRAMS
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
HADRONS
MATHEMATICAL MODELS
PARTICLE MODELS
PARTICLE PROPERTIES
POSTULATED PARTICLES
QUANTUM FIELD THEORY
RENORMALIZATION
662230* - Quantum Chromodynamics- (1992-)
662240 - Models for Strong Interactions- (1992-)