Transverse Target Single Spin Asymmetry in Elastic e-{\p} Scattering

TL;DR

This paper calculates the azimuthal single spin asymmetry in elastic electron-nucleon scattering caused by the transverse polarization of the nucleon, revealing how transverse charge density distortion leads to measurable asymmetries.

Contribution

It introduces a novel calculation of azimuthal asymmetry using the Coulomb Eikonal Phase and relativistic Eikonal approximation, linking transverse charge density distortion to observable asymmetries.

Findings

Azimuthal asymmetry arises from transverse charge density distortion.

Interference between one and two photon exchange amplitudes causes the asymmetry.

The approach provides a new way to probe nucleon transverse structure.

Abstract

Using the Coulomb Eikonal Phase associated with a transversely polarized nucleon, we calculate the azimuthal single spin asymmetry of unpolarized electrons elastically scattered from a transversely polarized nucleon target. The azimuthal asymmetry in this case is attributed to the fact that in a transversely polarized nucleon, the transverse charge density is no longer axially symmetric and is distorted due to the transverse spin of the nucleon. This asymmetry in the nucleon charge density causes a left-right asymmetry in the azimuthal distribution of the scattered electrons. In our approach, we utilize the relativistic Eikonal approximation to calculate the one and two photon exchange amplitudes from which a non zero azimuthal asymmetry appears due to the interference between the two amplitudes.