Scattering in an environment

TL;DR

This paper calculates the elastic electron-proton scattering cross section in an electron gas using the Closed Time Path method, revealing dominant entanglement effects near the Fermi energy that influence the classicality and irreversibility of collisions.

Contribution

It introduces a novel calculation of scattering cross sections in an electron gas, highlighting the significant role of entanglement effects near the Fermi energy.

Findings

Entanglement term dominates near Fermi energy.

Scattering becomes more classical and irreversible.

Trajectories are more consistent due to gas effects.

Abstract

The cross section of elastic electron-proton scattering taking place in an electron gas is calculated within the Closed Time Path method. It is found to be the sum of two terms, one being the expression in the vacuum except that it involves dressing due to the electron gas. The other term is due to the scattering particles-electron gas entanglement. This term dominates the usual one when the exchange energy is in the vicinity of the Fermi energy. Furthermore it makes the trajectories of the colliding particles more consistent and the collision more irreversible, rendering the scattering more classical in this regime.