Decuplet baryon magnetic moments in a QCD-based quark model beyond quenched approximation

Abstract

We study the decuplet baryon magnetic moments in a QCD-based quark model beyond quenched approximation. Our approach for unquenching the theory is based on the heavy baryon perturbation theory in which the axial couplings for baryon - meson and the meson-meson-photon couplings from the chiral perturbation theory are used together with the QM moment couplings. It also involves the introduction of a form factor characterizing the structure of baryons considered as composite particles. Using the parameters obtained from fitting the octet baryon magnetic moments, we predict the decuplet baryon magnetic moments. The $Ω^-$ magnetic moment is found to be in good agreement with experiment: $μ_{Ω^-}$ is predicted to be $-1.97 μ_N$ compared to the experimental result of ($-$2.02 $\pm$ 0.05) $μ_N$.