Baryon magnetic moments in a QCD-based quark model with loop corrections

Journal Article · Sun Nov 01 04:00:00 EST 1998 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.58.093008· OSTI ID:662322

Ha, P; Durand, L ^[1]

---

1. Physics Department, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

We study meson loop corrections to the baryon magnetic moments starting from a QCD-based quark model derived earlier in a quenched approximation to QCD. The model reproduces the standard quark model with extra corrections for the binding of the quarks. The loop corrections are necessary to remove the quenching. Our calculations use heavy baryon perturbation theory with chiral baryon-meson couplings, the quark model moment couplings, and a form factor characterizing the structure of baryons as composite particles. The form factor reflects soft wave function effects with characteristic momenta {approx}400thinspMeV, well below the usual chiral cutoff of {approx}1thinspGeV. The resulting model involves only three parameters, the quark moments {mu}{sub u} and {mu}{sub s}, and a parameter {lambda} that sets the momentum scale in the wave functions. We find that this approach substantially improves the agreement between the theoretical and experimental values of the octet baryon magnetic moments, with an average difference between the theoretical and experimental moments of 0.05{mu}{sub N}. An extension to the decuplet states using the same input predicts a moment of 1.97thinsp{mu}{sub N} for the {Omega}{sup {minus}} hyperon, in excellent agreement with the measured moment of 2.02{plus_minus}0.05thinsp{mu}{sub N}. {copyright} {ital 1998} {ital The American Physical Society}

• OSTI ID: 662322
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 9 Vol. 58; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BARYONS
MAGNETIC MOMENTS
QUANTUM CHROMODYNAMICS
QUARK MODEL