Flavor asymmetry of polarized antiquark distributions and semi-inclusive DIS

TL;DR

This paper investigates the flavor asymmetry of polarized antiquark distributions in the nucleon using the large-$N_c$ expansion and chiral quark-soliton model, and compares predictions with semi-inclusive DIS data.

Contribution

It demonstrates that large flavor asymmetries predicted by the chiral quark-soliton model are consistent with recent experimental data on spin asymmetries.

Findings

Large flavor asymmetries in polarized antiquark distributions are predicted.

Model results agree with HERMES semi-inclusive DIS data.

Flavor asymmetries significantly affect spin asymmetries in hadron production.

Abstract

The $1/N_c$-expansion of QCD suggests large flavor asymmetries of the polarized antiquark distributions in the nucleon. This is confirmed by model calculations in the large-$N_c$ limit (chiral quark-soliton model), which give sizable results for $\Delta\bar u (x) - \Delta\bar d (x)$ and $\Delta\bar u (x) + \Delta\bar d (x) - 2 \Delta \bar s (x)$. We compute the contributions of these flavor asymmetries to the spin asymmetries in hadron production in semi-inclusive deep-inelastic scattering. We show that the large flavor asymmetries predicted by the chiral quark-soliton model are consistent with the recent HERMES data for spin asymmetries in charged hadron production.