Physicists Confirm Quantum Entanglement Between Heavy Z Bosons in Higgs Decays
Researchers at the ATLAS experiment have found strong evidence that Z-boson pairs produced in Higgs decays are quantum-entangled, surviving the extreme conditions of the Large Hadron Collider.
In a study using data from CERN’s Large Hadron Collider, scientists examined Higgs boson decays that produce pairs of Z bosons, which quickly decay into electrons or muons. By measuring the emission angles of these decay products, they inferred the original Z bosons’ spin orientations and detected the quantum-entanglement signatures predicted by theory. The findings, reported by an international collaboration including University of Oxford researchers, constitute the most energetic test of entanglement to date.
Professor Alan Barr noted that observing entanglement in such heavy, fleeting particles underscores its fundamental nature. The results also bridge quantum information science and high-energy physics, suggesting new methods for probing beyond-Standard-Model phenomena. The paper appears in Physical Review Letters, and the ATLAS detector is slated for upgrades that will enable even more precise quantum studies.
