Chiral quark model of nucleon spin-flavor structure with SU(3) and axial-U(1) breakings

Journal Article · Thu Jan 01 04:00:00 EST 1998 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.57.344· OSTI ID:566121

Cheng, T P ^[1]; Li, L ^[2]

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1. Department of Physics and Astronomy, University of Missouri, St. Louis, Missouri 63121 (United States)
2. Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)

The chiral quark model with a nonet of Goldstone bosons can yield an adequate description of the observed proton flavor and spin structure. In a previous publication we have compared the results of an SU(3) symmetric calculation with the phenomenological findings based on experimental measurements and SU(3) symmetry relations. In this paper we discuss their SU(3) and axial U(1) breaking corrections. Our result demonstrates the broad consistency of the chiral quark model with the experimental observations of the proton spin-flavor structure. With two parameters, we obtain a very satifactory fit to the F/D ratios for the octet baryon masses and for their axial vector couplings, as well as the different quark flavor contributions to the proton spin. The result also can account for not only the light quark asymmetry {bar u}{minus}{bar d} but also the strange quark content {bar s} of the proton sea. SU(3) breaking is the key in reconciling the {bar s} value as measured in the neutrino charm production and that as deduced from the pion nucleon {sigma} term. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 566121
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 1 Vol. 57; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CHARM PARTICLES
CHIRAL SYMMETRY
FLAVOR
GOLDSTONE BOSONS
NEUTRINOS
NUCLEONS
PROTONS
QUARK MODEL
SPIN
SU-3 GROUPS
SYMMETRY BREAKING
U-1 GROUPS