Testing spooky action between free-traveling electron-positron pairs

TL;DR

This paper demonstrates the feasibility of measuring polarization correlations and Bell inequality violations in free-traveling electron-positron pairs generated in a fixed-target experiment, advancing understanding of high-energy quantum entanglement.

Contribution

It introduces a controllable source of entangled free-traveling electron-positron pairs and shows how to measure their polarization correlations through secondary scatterings.

Findings

Feasibility of measuring polarization correlations in free electron-positron pairs.

Demonstration of Bell inequality violation in high-energy entangled pairs.

Development of a method to generate and analyze entangled pairs in a fixed-target setup.

Abstract

Quantum entanglement is a cornerstone of quantum mechanics. While the entanglement of confined electron pairs has been established early on, the entanglement of free-traveling electron pairs, particularly at high energies, remains largely unexplored due to the substantial challenges involved in measuring the spins of free-traveling electrons. In this study, we investigate the entanglement and the Bell inequality violation of free-traveling electron-positron pairs generated in a fixed-target experiment. This experimental setup facilitates the creation of a controllable source of entangled electron-positron pairs, where entangled events are produced in specific phase spaces. Based on this source and the prior knowledge of the entangled state, we demonstrate the feasibility of measuring the polarization correlations of the entangled $e^+e^-$ pairs through their individual secondary scatterings off two separate additional targets.