Scientists at the Brookhaven National Laboratory of the US Department of Energy have developed a new method to explore the internal structure of protons using data generated by high-energy particle collisions. Combining quantum information science, they studied the trajectories of particles released during electron proton collisions and how they are influenced by quantum entanglement between quarks and gluons within protons. This result was published in the latest issue of the Journal of Advances in Physics, revealing the phenomenon of quantum entanglement within protons. Protons are composed of quarks and gluons, and the quantum entanglement between these fundamental particles is a special phenomenon where particles can "perceive" each other's states, such as their spin direction, even when they are far apart. Einstein once vividly referred to this phenomenon as "distant ghostly interactions". But this time, entanglement occurred at an extremely small distance, less than one billionth of a meter inside the proton, and this information exchange covered the entire collection of quarks and gluons inside the proton. The team used quantum information methods to predict how quantum entanglement affects the particles that flow out after collision. According to their calculations, when quarks and gluons within a proton are in a state of maximum entanglement, i.e. have the highest 'entanglement entropy', collisions should produce a large number of randomly distributed particles, exhibiting a high level of entropy. They analyzed proton proton collision data from the European Large Hadron Collider, as well as clearer electron proton collision data. The actual observed data is found to be completely consistent with theoretical predictions, indicating that quarks and gluons inside protons are indeed in a state of maximum entanglement. Entanglement is a systematic interaction that involves the collective behavior of the entire system, rather than the behavior of individual particles. Just as people cannot understand the temperature of boiling water solely by considering the motion of each water molecule in the pot, they cannot understand the overall properties of protons solely based on the behavior of individual quarks or gluons. Instead, they need to consider the collective combination behavior of all particles. When a large number of particles work together, the physical rules will change. Quantum information provides tools to describe this behavior, helping people better understand how particle entanglement guides collective behavior. This study not only enhances people's understanding of the internal structure of protons, but also provides new insights for other scientific fields involving entanglement. (New Society)