CERN Scientists Observe Quantum Entanglement in Three-State Systems
Researchers at CERN have found strong evidence of quantum entanglement between Z bosons produced from Higgs boson decays, marking a significant step in understanding multi-state quantum systems.
In a groundbreaking discovery, physicists at CERN’s Large Hadron Collider (LHC) have reported strong evidence for quantum entanglement between pairs of Z bosons that originate from the decay of a Higgs boson. This finding, announced on September 17, 2026, represents the first observation of entanglement in a three-state quantum system, known as a qutrit, moving beyond the more commonly studied two-state qubits Strong evidence for quantum entanglement between Z bosons found by ATLAS and CMS — CERN.
The ATLAS and CMS collaborations at the LHC analyzed data from proton-proton collisions at energies up to 13.6 TeV. Their analysis indicated that the Z bosons exhibited entangled properties, a phenomenon where particles remain connected and influence each other instantaneously, regardless of the distance separating them. This observation was made with a statistical significance of 4.7 standard deviations, a threshold generally considered strong evidence in particle physics ATLAS explores quantum entanglement using Higgs boson decays, while charting its properties — ATLAS Experiment at CERN.
This achievement is particularly notable because Z bosons possess three possible spin states, distinguishing them from systems typically studied, which are limited to two states (qubits). The observation of entanglement in a qutrit system opens up new avenues for exploring the complexities of quantum mechanics Strong evidence for quantum entanglement between Z bosons found by ATLAS and CMS — CERN.
The research published in Physical Review Letters on September 11, 2026, also sheds light on the nature of virtual particles. Due to energy conservation constraints during the decay process, at least one of the Z bosons involved in the entanglement must be virtual. This raises intriguing questions about whether such fleeting, virtual particles can participate in the phenomenon of quantum entanglement CERN Detects Quantum Entanglement in Particles Born From The Higgs Boson — ScienceAlert.
The use of Higgs boson decays as a source for these entangled Z bosons provides a unique laboratory for probing these fundamental quantum phenomena. The Higgs boson, known for its role in giving mass to other particles, acts as a parent particle from which the entangled pair emerges CERN Detects Quantum Entanglement in Particles Born From The Higgs Boson — ScienceAlert.
The statistical significance of 4.7 sigma achieved by the ATLAS experiment means that the probability of observing such results if the particles were not entangled is very low, lending substantial weight to the evidence for entanglement ATLAS explores quantum entanglement using Higgs boson decays, while charting its properties — ATLAS Experiment at CERN.
This discovery is a significant milestone in quantum physics, demonstrating the entangled nature of particles originating from fundamental interactions within the Standard Model. It paves the way for future experiments that could explore entanglement in even more complex systems and potentially probe deeper into the quantum realm Strong evidence for quantum entanglement between Z bosons found by ATLAS and CMS — CERN.
Further research will likely focus on understanding the implications of virtual particles participating in entanglement and exploring the potential applications of qutrit entanglement in quantum computing and information processing.