Influence of Coulomb distortion on polarization observables in elastic electromagnetic lepton hadron scattering at low energies

TL;DR

This paper derives a general expression for polarization observables in low-energy elastic lepton-hadron scattering, analyzing how Coulomb distortion affects these observables through detailed calculations including hyperfine and spin-orbit interactions.

Contribution

It introduces a formal expression for polarization observables considering Coulomb distortion effects in the nonrelativistic regime, extending previous models.

Findings

Coulomb repulsion significantly reduces polarization observables for like charges.

Coulomb attraction enhances polarization observables for opposite charges below 20 keV.

The study provides detailed quantitative analysis of Coulomb effects on polarization in low-energy scattering.

Abstract

The formal expression for the most general polarization observable in elastic electromagnetic lepton hadron scattering at low energies is derived for the nonrelativistic regime. For the explicit evaluation the influence of Coulomb distortion on various polarization observables is calculated in a distorted wave Born approximation. Besides the hyperfine interaction also the spin-orbit interactions of lepton and hadron are included. For like charges the Coulomb repulsion reduces strongly the size of polarization observables compared to the plane wave Born approximation whereas for opposite charges the Coulomb attraction leads to a substantial increase of these observables for hadron lab kinetic energies below about 20 keV.