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

We study the decuplet baryon magnetic moments in a QCD-based quark model beyond the quenched approximation. Our approach for unquenching the theory is based on heavy baryon perturbation theory in which the axial couplings for baryon-meson and the meson-meson-photon couplings from chiral perturbation theory are used together with the quark model 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 -1.97μ_N compared to the experimental result of (-2.02 ± 0.05) μ_N.