Helicity skewed quark distributions of the nucleon and chiral symmetry

Abstract

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