Probing quantum entanglement with Generalized Parton Distributions at the Electron-Ion Collider

TL;DR

This paper investigates quantum entanglement in quark-antiquark pairs produced in electron-proton scattering using GPDs, predicting polarization effects and mapping entanglement regions at the Electron-Ion Collider.

Contribution

It introduces a framework to analyze entanglement, Bell nonlocality, and polarization of quark pairs in electron-proton collisions within the GPD approach.

Findings

Identifies kinematic regions with entanglement, Bell nonlocality, and non-stabilizerness.

Predicts high transverse polarization (50-80%) for massive quarks in certain regions.

Maps polarization patterns for strangeness, charm, and bottom production.

Abstract

Within the collinear factorization framework based on Generalized Parton Distributions (GPDs), we calculate the spin density matrix of exclusively produced quark and antiquark pairs $u\bar{u}$, $d\bar{d}$, $s\bar{s}$, $c\bar{c}$, $b\bar{b}$ in electron-proton scattering. The presence of both real and imaginary parts in the scattering amplitudes leads to a rich pattern of entanglement between the quark and the antiquark. We map out kinematical regions where the pairs exhibit entanglement, Bell nonlocality and non-stabilizerness (`magic'). We also predict that massive quarks and antiquarks are transversely polarized, similar to the well-known transverse hyperon polarization in unpolarized collisions. In strangeness, charm and bottom productions, the polarization can reach 50-80\% in certain kinematic regions in the low-energy runs of the Electron-Ion Collider.