Polarization Effects in Two-Photon Free-Free Transitions in Laser-Assisted Electron-Hydrogen Collisions

TL;DR

This paper investigates how laser field polarization influences two-photon free-free transition cross sections in high-energy electron-hydrogen collisions, providing detailed analytical and numerical insights.

Contribution

It offers a comprehensive third-order perturbation theory analysis including all Feynman diagrams, highlighting polarization effects on differential cross sections.

Findings

Polarization significantly affects angular distributions.

Frequency dependence varies with field polarization.

Analytical expressions enable precise cross section calculations.

Abstract

Two-photon free-free transitions in elastic laser-assisted electron-hydrogen collisions are studied in the domain of high scattering energies and low or moderate field intensities, in the third order of perturbation theory, taking into account all the involved Feynman diagrams. Based on the analytical expressions of the transition amplitudes, the differential cross sections for two-photon absorption/emission are computed at impact energy $E_i=100$ eV. The effect of field polarizations on the angular distribution and on the frequency dependence of the differential cross section is analyzed.