Their approach uses quantum information science to map out how particle tracks streaming from electron-proton collisions are influenced by quantum entanglement inside the proton.

The results reveal that quarks and gluons, the fundamental building blocks that make up a proton's structure, are subject to so-called quantum entanglement. This quirky phenomenon, famously described by Albert Einstein as "spooky action at a distance," holds that particles can know one another's state—for example, their spin direction—even when they are separated by a great distance.