Axial charges of the proton within an extended chiral constituent quark model

We have performed a study of the isovector, octet, and singlet axial charges of the proton in an extended chiral constituent quark model, where all the possible uudq ($) over bar (q = u, d, s) five-quark Fock components in the proton wave function are taken into account. The P-3(0) quark-antiquark creation mechanism is assumed to account for the transition coupling between three- and five-quark components in proton, and the corresponding transition coupling strength is fixed by fitting the intrinsic sea flavor asymmetry (d) over bar - (u) over bar data for proton. Accordingly, with all the parameters fixed by empirical values, the probabilities of the intrinsic five-quark Fock components in proton wave function should be similar to 30-50%, which lead to the numerical results for quark spin Delta u, Delta d, and Delta s, as well the axial charges of proton consistent with the experimental data and predictions by other theoretical approaches.

Automated summary

In this study, an extended chiral constituent quark model was used to analyze the axial charges of the proton, taking into account all possible five-quark Fock components in the proton wave function. The P-3(0) quark-antiquark creation mechanism was utilized to explain the transition coupling between different quark components, leading to numerical results consistent with experimental data.