Entanglement Entropy in ttbar Transverse Momentum Differential Cross Section Distributions

We explore a novel method for studying proton-proton collisions, using both ATLAS and CMS results. Since both protons are initially in a pure state, we note that after the protons collide, their overlap region (collision region) is entangled with the non-overlap region (spectator region). The degree of entanglement between these two regions is given by the entanglement entropy. This idea is supported by showing that the ttbar differential cross section results at various transverse momenta can be described by a fit with a thermal component and a hard scattering component. When the collision and spectator regions are entangled, there is both a thermal and a hard scattering component. Consequently, when there is no entanglement present, only the hard scattering component survives.