Magnetic moments of octet baryons, angular momenta of quarks and sea antiquark polarizations

TL;DR

This paper combines experimental data and theoretical models to determine antiquark polarizations in the proton, utilizing magnetic moments, deep inelastic scattering, and lattice calculations, and finds results consistent with recent experiments.

Contribution

It introduces a method to fix parameters for antiquark polarization calculations using magnetic moments and recent experimental data, improving understanding of proton structure.

Findings

Antiquark polarization difference aligns with HERMES results.

Parameters constrained by $eta$ decay and magnetic moment fits.

Orbital angular momenta from lattice calculations support the analysis.

Abstract

One can determine antiquark polarizations in proton using the information from deep inelastic scattering, $\beta$ decays of baryons, orbital angular momenta of quarks, as well as their integrated magnetic distributions. The last quantities were determined previously by us performing a fit to magnetic moments of baryon octet. However, because of the SU(3) symmetry our results depend on two parameters. The quantity $\Gamma_{V}$, measured recently in a COMPASS experiment, gives the relation between these parameters. We can fix the last unknown parameter using the ratio of up and down quark magnetic moments which one can get from the fit to radiative vector meson decays. We calculate antiquark polarizations with the orbital momenta of valence quarks that follow from lattice calculations. The value of difference for up and down antiquark polarizations obtained in our calculations is consistent with the result obtained in a HERMES experiment.