The entanglement properties of systems in which elastic and inelastic reactions occur in projectile-target interactions is studied. A new measure of entanglement, the scattering entropy, based on the unitarity of the $S$ matrix (probability conservation), is suggested. Using simple models for both low- and high-energy interactions, the amount of entanglement is found to track with the strength of the inelastic interaction. The familiar example of the classical “black disk,” or total absorption, model is found to correspond to maximum entanglement. An analysis of high-energy $pp$ scattering data shows that entanglement is near maximum for laboratory energies greater than about 1 GeV, showing that the total absorption model is a reasonable starting point for understanding the data.

Close

PrevNext

View figure in article

• Elastic scattering reactions
• Inelastic scattering reactions
• Nuclear reactions
• Particle interactions