Analysis of dynamical corrections to baryon magnetic moments

Abstract

We present and analyze QCD corrections to the baryon magnetic moments in terms of the one-, two-, and three-body operators which appear in the effective field theory developed in our recent papers. The main corrections are extended Thomas-type corrections associated with the confining interactions in the baryon. We investigate the contributions of low-lying angular excitations to the moments quantitatively and show that they are completely negligible. When the QCD corrections are combined with the non-quark model contributions of the meson loops, we obtain a model which describes the moments within a mean deviation of 0.04 ${\mu }_N$. The nontrivial interplay of the two types of corrections to the quark-model moments is analyzed in detail, and explains why the quark model is so successful. In the course of these calculations, we parametrize the general spin structure of the $j={1/2}^{+}$ baryon wave functions in a form which clearly displays the symmetry properties and the internal angular momentum content of the wave functions, and allows us to use spin-trace methods to calculate the many spin matrix elements which appear in the expressions for the moments. This representation may be useful elsewhere.

32 pages, 3 figures, submitted to Phys. Rev. D

References in corpus (5)

• Octet baryon magnetic moments in light cone QCD sum rules
• Baryon magnetic moments in the effective quark Lagrangian approach
• Effective field theory and the quark model
• Spin-dependent forces of quarks in baryon
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• Strange form factors of nucleon with nonlocal chiral effective Lagrangian
• Electromagnetic corrections to baryon masses
• Nucleon magnetic form factors with non-local chiral effective Lagrangian
• Estimates of isospin breaking contributions to baryon masses