Entanglement entropy of particles in a perturbative scattering

TL;DR

This paper investigates the entanglement entropy in QED scattering processes using perturbative methods and dressed states to handle infrared divergences, revealing a linear distribution of entanglement over the cross section.

Contribution

It introduces a perturbative approach combined with dressed states to accurately compute entanglement entropy in scattering, addressing infrared divergences.

Findings

Entanglement entropy is linearly distributed over the scattering cross section.

Dressed state formalism effectively manages infrared divergences in entropy calculations.

Perturbative corrections improve the accuracy of entanglement measures in QED processes.

Abstract

The entanglement among scattering particles in an exemplary quantum electrodynamics (QED) process is studied perturbatively. To increase the computational accuracy, we need to consider virtual photon loop diagrams, which lead to infrared divergence. Therefore, when including higher-order corrections in perturbative theory, we use the dressed state formalism proposed by Chuang and Faddeev-Kulish, which provides a finite S-matrix element. The entanglement entropy calculation shows that the entanglement is distributed linearly over the scattering cross section under the perturbation approximation