Testing Bell inequalities at the LHC with top-quark pairs

TL;DR

This paper proposes using top-quark pair spin entanglement at the LHC to test Bell inequalities at unprecedented energies, demonstrating that existing and future data can reveal quantum nonlocality with high confidence.

Contribution

It introduces a method to test Bell inequalities using top-quark spin measurements at the LHC, achieving significant statistical confidence with current and future data.

Findings

Bell inequality violation can be tested at the LHC.

Existing data already allows a 98% CL test.

Future runs can reach 99.99% CL significance.

Abstract

Entanglement between the spins of top-quark pairs produced at a collider can be used to test a (generalized) Bell inequality at energies never explored so far. We show how the measurement of a single observable can provide a test of the violation of the Bell inequality at the 98% CL with the data already collected at the Large Hadron Collider and at the 99.99% CL with the higher luminosity of the next run.