Helicity skewed quark distributions of the nucleon and chiral symmetry

TL;DR

This paper calculates helicity skewed quark distributions in the nucleon using a chiral quark-soliton model, highlighting the importance of chiral symmetry and pion pole contributions at low momentum transfer.

Contribution

It introduces a calculation of helicity skewed quark distributions within the chiral quark-soliton model, emphasizing chiral symmetry effects and pion pole dominance.

Findings

Pion pole contribution dominates in -ξ < x < ξ region.

Chiral symmetry plays a crucial role in skewed quark distributions.

Model provides leading twist distributions at low normalization point.

Abstract

We compute the helicity skewed quark distributions $\widetilde{H}$ and $\widetilde{E}$ in the chiral quark-soliton model of the nucleon. This model emphasizes correctly the role of spontaneously broken chiral symmetry in structure of nucleon. It is based on the large-N_c picture of the nucleon as a soliton of the effective chiral lagrangian and allows to calculate the leading twist quark- and antiquark distributions at a low normalization point. We discuss the role of chiral symmetry in the helicity skewed quark distributions $\widetilde{H}$ and $\widetilde{E}$. We show that generalization of soft pion theorems, based on chiral Ward identities, leads in the region of -\xi < x < \xi to the pion pole contribution to $\widetilde{E}$ which dominates at small momentum transfer.