Double Spin Asymmetries through QCD Instantons

TL;DR

This paper investigates how QCD instantons significantly influence spin asymmetries in polarized proton collisions, predicting large effects in double spin asymmetry measurements.

Contribution

It demonstrates the sizable impact of instantons on spin asymmetries and predicts a large double spin asymmetry in polarized proton collisions.

Findings

Instantons contribute sizably to single spin asymmetry.

Prediction of a large double spin asymmetry in polarized proton collisions.

Revisits and extends previous instanton-related spin asymmetry studies.

Abstract

We revisit the large instanton contribution to the gluon Pauli form factor of the constituent quark noted by Kochelev. We check that it contributes sizably to the single spin asymmetry in polarized $p_\uparrow p \rightarrow \pi X$. We use it to predict a large double spin asymmetry in doubly polarized $p_\uparrow p_\uparrow\rightarrow \pi \pi X$.