Phenomenological SU(6) breaking of baryon wave functions and the chromodynamic spin-spin force

Journal Article · Fri Sep 01 04:00:00 EDT 1978 · Phys. Rev., D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.18.1591· OSTI ID:6670239

Le Yaouanc, A; Oliver, L; Pene, O; Raynal, J C

A contradiction is found between two successful models of SU(6) breaking. A quark-model mixing scheme (56,0/sup +/) + (70,0/sup +/) for the baryon octet has been devised to explain the ratio F/sup e/n/sub 2/(x)/F/sup e/p/sub 2/(x) in the valence-quark region and explains naturally other departures from the usual SU(6) predictions. On the other hand, the gluon-exchange model of SU(6) breaking accounts satisfactorily for the hadron spectrum splittings. The spin-spin contribution from this chromodynamic force is indeed shown to generate a (56,0/sup +/) + (70,0/sup +/) mixing of the octet. However, it yields a wrong sign for the mixing angle, thus pointing to a contradiction between spin-spin forces of one-gluon-exchange type and the deep-inelastic structure functions in the valence-quark region. Other spin-spin potentials, giving the right sign for the mixing angle, are shown to be also in difficulty, because of the hyperfine structure of excited levels. Finally, a careful discussion is made of the subtle ..sigma..-..lambda.. effect in both approaches.

• Research Organization: Laboratoire de Physique Theorique et Hautes Energies, Orsay, France
• OSTI ID: 6670239
• Journal Information: Phys. Rev., D; (United States), Journal Name: Phys. Rev., D; (United States) Vol. 18:5; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

645303* -- High Energy Physics-- Particle Invariance Principles & Symmetries-- Applications to Strong Interactions-- (-1987)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYON OCTETS
COMPOSITE MODELS
COUPLING
ENERGY LEVELS
EXCHANGE INTERACTIONS
EXCITED STATES
FUNCTIONS
GLUON MODEL
INTERACTIONS
INTERMEDIATE COUPLING
J-J COUPLING
LIE GROUPS
MATHEMATICAL MODELS
MULTIPLETS
PARTICLE MODELS
PARTICLE MULTIPLETS
QUARK MODEL
SU GROUPS
SU-6 GROUPS
SYMMETRY BREAKING
SYMMETRY GROUPS
WAVE FUNCTIONS