An international team of physicists has studied how particles are produced in high-energy electron–proton collisions through the lens of entanglement entropy
Entanglement is fundamental to our understanding of the microscopic world and remains one the strangest aspects of quantum mechanics.
There are various ways to quantify the level of entanglement in quantum systems. One of these measures is called entanglement entropy.
In this context, entropy refers to the minimum amount of information required to describe a system. A system with high entropy requires a lot of information to describe it. This also means that it contains a large amount of uncertainty.
In recent years, there has been a growing interest in quantum entanglement within high-energy physics, for example in understanding the structure of protons and other hadrons.
Hadrons themselves are made up of quarks, which are tightly bound together via exchanges of gluons. The properties of these hadrons can be calculated using our best theory of the strong force – quantum chromodynamics (QCD) – but this is usually very challenging.
In this work, the team investigated how entanglement entropy evolves in high-energy processes. They particularly focused on deep inelastic scattering, where a high-energy electron probes the internal structure of a proton.
By examining how entanglement entropy depends on velocity, the researchers connected theoretical predictions with experimental data on hadron production.
Their results suggest that, in many cases, a state of maximum entanglement is reached. This is where the particles are as strongly correlated as quantum mechanics allows.
The team’s work will lead to a deeper understanding of fundamental QCD processes and help bridge the gap between theoretical predictions and experimental observations of particle collisions.
