Interpretations of Elastic Electron Scattering

TL;DR

This paper investigates how the interpretation of elastic electron scattering data, specifically the charge and magnetic radii of nucleons and nuclei, varies between the Breit and laboratory reference frames, affecting form factor ratios and radius measurements.

Contribution

It introduces a toy model to estimate frame-dependent modifications of nucleon and nuclear charge and magnetic radii, impacting the analysis of scattering experiments.

Findings

Model predicts corrections to nucleon charge radii between frames

Implications for proton form factor ratio analysis

Provides correction estimates for light nuclei radii

Abstract

Elastic scattering of relativistic electrons from the nucleon yields Lorentz invariant form factors that describe the fundamental distribution of charge and magnetism. The spatial dependence of the nucleon's charge and magnetism is typically interpreted in the Breit reference frame which is related by a Lorentz boost from the laboratory frame, where the nucleon is at rest. We construct a toy model to estimate how the charge and magnetic radii of the nucleon are modified between the Breit and lab. frames. This has implications for the ratio of the proton electric to magnetic elastic form factors as a function of momentum transfer as well as for determinations of the proton charge radius. Predicted corrections based on the model are provided for the rms charge radii of the deuteron, the triton, and the helium isotopes.