Quantum entanglement and bell nonlocality at future lepton colliders

Quantum entanglement and Bell nonlocality—cornerstones of quantum mechanics—have traditionally been investigated only in low-energy experimental settings. Only recently, these fundamental phenomena have come to be explored in the high-energy domain of particle physics, where collider experiments offer a powerful new platform for studying the phenomenology of quantum correlations. We present here recent results on the detection of entanglement and Bell nonlocality in processes such as tau–lepton, WW, and ZZ pair production, illustrating the potential of future lepton colliders to probe the quantum properties of fundamental interactions.