The elastic electron-deuteron scattering beyond one-photon exchange

TL;DR

This paper analyzes elastic electron-deuteron scattering beyond the one-photon exchange approximation, identifying key form factors and the dominant two-photon exchange diagrams affecting the reaction cross section.

Contribution

It introduces a framework with six generalized form factors, highlights three independent combinations relevant to the cross section, and assesses the significance of different two-photon exchange diagrams.

Findings

Three form factors dominate the cross section.

Two-photon exchange with same-nucleon interaction is the main contribution.

Nonrelativistic calculations support the dominance of certain diagrams.

Abstract

We discuss the elastic ed scattering beyond Born approximation. It is shown that the reaction amplitude contains six generalized form factors, but only three linearly independent combinations of them (we call them generalized charge, quadrupole and magnetic form factors) contribute to the reaction cross section in the second order perturbation theory. We examine two-photon exchange and find that it includes two types of diagrams, when two virtual photons interact with the same nucleon and when the photons interact with different nucleons. Estimations based on nonrelativistic calculations with the deuteron wave function for realistic NN potential show that the main contribution to the generalized charge, quadrupole and magnetic form factors comes from diagrams of the first type.