Studying Maximal Entanglement and Bell Nonlocality at an Electron-Ion Collider

TL;DR

This paper explores the potential of the Electron-Ion Collider to test quantum entanglement and Bell nonlocality through spin correlation measurements in quark-antiquark pairs, highlighting the collider's advantages over hadron colliders.

Contribution

It introduces a novel approach to studying entanglement and Bell nonlocality at the EIC by analyzing photon polarization effects on spin correlations in quark-antiquark production.

Findings

Longitudinally polarized photons produce maximal entanglement.

Transversely polarized photons generate significant entanglement near threshold.

EIC offers a cleaner environment for measuring quantum entanglement.

Abstract

In this paper, we propose to test quantum entanglement and Bell nonlocality at an Electron-Ion Collider (EIC). By computing the spin correlations in quark-antiquark pairs produced via photon-gluon fusion, we find that longitudinally polarized photons produce maximal entanglement at leading order, while transversely polarized photons generate significant entanglement near the threshold and in the ultra-relativistic regime. Compared to hadron colliders, the EIC provides a cleaner experimental environment for measuring entanglement through the $\gamma^\ast g \to q\bar{q}$ channel, offering a strong signal and a promising avenue to verify Bell nonlocality. This study extends entanglement measurements to the EIC, presenting new opportunities to explore the interplay of quantum information phenomena and hadronic physics in the EIC era.