Two-photon exchange and elastic scattering of longitudinally polarized electron on polarized deuteron

TL;DR

This paper investigates the impact of two-photon exchange processes on elastic scattering of polarized electrons on polarized deuterons, revealing their significant effects on certain structure functions and polarization observables.

Contribution

It provides a detailed analysis of two-photon exchange contributions to polarization observables in electron-deuteron scattering, highlighting their importance beyond one-photon exchange approximation.

Findings

Two-photon exchange affects structure function A by a few percent.

Two-photon exchange influences structure function B by 10-20%.

Certain polarization observables are sensitive to interference effects.

Abstract

Structure functions and polarization observables in elastic scattering of longitudinally polarized electron on polarized deuteron are considered within approximation of one-photon + two-photon exchange. It is shown that contribution of two-photon exchange in the generalized structure function A is of order of few percent, while in the generalized structure function B it is of order of 10--20 %. We have found that components T_{20} and T_{21} of tensor analyzing power are mainly determined by one-photon exchange, but T_{22} is mainly determined by interference between one-photon exchange and two-photon exchange. We have also considered polarization observables T_{11}, C_{21} and C_{22} which are proportional to imaginary part of the reaction amplitude and vanish in the framework of one-photon exchange.