Abstract
The Standard Model of particle physics is a quantum field theory, based on quantum mechanics and special relativity. Collider processes allow us to test fundamental properties of quantum mechanics. Higgs decays H → ZZ → 4 leptons are a unique high-energy system in which spin entanglement is predicted to be nearly maximal, and spin correlations can be cleanly measured. Thus, it is possible to study fundamental aspects of quantum mechanics such as entanglement. We will discuss the theoretical background, the spin correlation measurements by the ATLAS and CMS Collaborations and their consequences in terms of entanglement and particle indistinguishability.
Speakers
Jeff Davis is a post-doctoral fellow at Johns Hopkins University. He received his PhD from Johns Hopkins in late 2025. Jeff is a member of the CMS collaboration where he works on measuring the properties of the Higgs boson using the four-lepton final state. His primary research interests are in effective field theory interpretations of Higgs boson and electroweak vector boson data, as well using Higgs decays to test the fundamental aspects of quantum mechanics.
Juan Antonio Aguilar Saavedra is a scientific researcher at CSIC (IFT/Madrid) since 2021, and associate professor on leave from the University of Granada. He obtained his PhD at the University of Granada, moved to Instituto Superior Técnico of Lisbon as a post-doc for 4 years, and returned to Granada where he taught for 15 years. He has worked on top quark physics, beyond-the-SM theories with vector-like quarks and leptons, effective field theory, jet tagging and anomaly detection, ambulance chasing, and in the last four years in tests of quantum foundations in high-energy physics, namely bipartite and tripartite entanglement, Bell nonlocality, identical-particles, and quantum interference effects.