Transverse strange quark spin structure of the nucleon

TL;DR

This paper explores the transverse spin densities of quarks, especially strange quarks, in the nucleon using the chiral quark-soliton model, revealing notable distortions for strange quarks in an unpolarized proton.

Contribution

It provides the first predictions of strange quark transverse spin densities within the chiral quark-soliton model, extending understanding of nucleon spin structure.

Findings

Transverse spin densities of up and down quarks agree with lattice results.

Strange quark spin density shows significant distortion in an unpolarized proton.

The model successfully predicts transverse spin densities for strange quarks.

Abstract

We investigate the transverse quark spin densities of the nucleon with the lowest moment within the framework of the SU(3) chiral quark-soliton model, emphasizing the strange quark spin density. Based on previous results of the vector and tensor form factors, we are able to determine the impact-parameter dependent probability densities of transversely polarized quarks in an unpolarized nucleon as well as those of unpolarized quarks in a transversely polarized nucleon. We find that the present numerical results for the transverse spin densities of the up and down quarks are in good agreement with those of the lattice calculation. We predict the transvere spin densities of the strange quark. It turns out that the polarized strange quark is noticeably distorted in an unpolarized proton.