Octet and Decuplet Baryon Magnetic Moments in the Chiral Quark Model

Abstract

Octet and decuplet baryon magnetic moments have been formulated within the \chiQM with configuration mixing incorporating the sea quark polarizations and their orbital angular momentum through the generalization of the Cheng-Li mechanism. When the parameters of \chiQM without configuration mixing are fixed by incorporating the latest data pertaining to $\bar u-\bar d$ asymmetry (E866) and the spin polarization functions, in the case of octet magnetic moments the results not only show improvement over the nonrelativistic quark model results but also give a non zero value for the right hand side of Coleman-Glashow sum rule, usually zero in most of the models. When effects of configuration mixing and ``mass adjustments'' due to confinement are included, in the case of p, \Sigma^+, \Xi^o, the \Sigma \Lambda transition magnetic moment and the violation of Coleman Glashow sum rule an almost perfect agreement with data is obtained. In the case of decuplet magnetic moments, we obtain a good overlap for \Delta^{++}, \Omega^- and the transition magnetic moment $\Delta N$ for which data are available. In case, we incorporate in our analysis the gluon polarization \Delta g, found phenomenologically through the relation \Delta\Sigma(Q^2)=\Delta\Sigma-\frac{3\alpha_s(Q^2)}{2\pi}\Delta g(Q^2), we not only obtain improvement in the quark spin distribution functions and magnetic moments but also the value of \Delta g comes out to be in good agreement with certain recent measurements as well as theoretical estimates.