Polarization effects in non-relativistic $ep$ scattering

TL;DR

This paper analytically calculates the spin-flip cross section in non-relativistic electron-proton scattering, revealing it is too small for practical beam polarization despite enhancement at low velocities.

Contribution

It provides an analytical calculation of polarization-dependent cross sections in non-relativistic $ep$ scattering, highlighting limitations for beam polarization applications.

Findings

Cross section is greatly enhanced at small velocities for attractive interactions.

The cross section remains very small, leading to impractically long polarization times.

Current $e^{ ext{±}}$$ beams are unsuitable for polarizing stored protons or antiprotons.

Abstract

The cross section which addresses the spin-flip transitions of a proton (antiproton) interacting with a polarized non-relativistic electron or positron is calculated analytically. In the case of attraction, this cross section is greatly enhanced for sufficiently small relative velocities as compared to the result obtained in the Born approximation. However, it is still very small, so that the beam polarization time turns out to be enormously large for the parameters of $e^{\pm}$ beams available now. This practically rules out a use of such beams to polarize stored antiprotons or protons.