Oxford Physicists Help Uncover ‘Spooky’ Quantum Effect in The Large Hadron Collider

Insider Brief

• ATLAS researchers found strong evidence of quantum entanglement between pairs of short-lived Z bosons produced by Higgs boson decays at CERN’s Large Hadron Collider.
• The team inferred the Z bosons’ spins by analyzing the angles of the electrons and muons produced when the bosons decayed.
• The findings provide one of the highest-energy confirmations of entanglement and could support more sensitive methods for analyzing particle-collider data.
• Image: The Large Hadron Collider (LHC) accelerator in the tunnel at CERN. (© 2009-2026 CERN)

PRESS RELEASE — Physicists at the University of Oxford have helped confirm that one of the strangest phenomena in physics – quantum entanglement – occurs even among some of the heaviest and most fleeting particles ever created. The discovery, made using the world’s most powerful particle collider at CERN, has been published in Physical Review Letters.

Entanglement is the phenomenon in which two particles from the same origin remain connected, even if they move far apart in time and space. If something affects one particle, it will also affect all the particles with which it is entangled. This means that measuring a property of one particle instantly tells you something about its entangled partner/s, no matter how distant they are.