Investigations on the flavor-dependent axial charges of the octet baryons

TL;DR

This paper investigates the flavor-dependent axial charges of octet baryons using an extended chiral constituent quark model that includes five-quark components, providing results consistent with lattice QCD and chiral perturbation theory.

Contribution

It introduces a comprehensive model incorporating five-quark states and the $^{3}P_{0}$ mechanism to better understand baryon axial charges and sea quark effects.

Findings

Axial charges are comparable to other theoretical predictions.

Singlet axial charges range from 0.45 to 0.75, aligning with lattice QCD.

Light quark spins in the Lambda baryon are small and negative.

Abstract

We have investigated the axial charges of the ground octet baryons within the extended chiral constituent quark model, where all the possible compact five-quark Fock components $qqq(q\bar{q}) (q=u, d, s)$ in the baryons are considered. The transition couplings between the three- and five-quark components in the baryons are assumed to be via the $^{3}P_{0}$ mechanism, which could reproduce the sea asymmetry in proton very well. The numerical results for the flavor-dependent axial charges of the octet baryons are comparable to those predicted by other theoretical approaches. It is shown that the singlet axial charges of the octet baryons, which should indicate total baryons spin arising from the spin of the quarks, fall in the range $0.45-0.75$ in present model. This is in consistent with the predictions by lattice QCD and chiral perturbation theory. It's also very interesting that the light quarks spin $\Delta u$ and $\Delta d$ in the $\Lambda$ baryon are of small but negative values, which exactly vanish in the traditional three-quark model.