Properties of the Sachs electric form factor of the proton on the basis of recent $e-p$ scattering experiments and hydrogen spectroscopy

TL;DR

This paper analyzes recent electron-proton scattering data to assess its consistency with hydrogen spectroscopy measurements and theoretical models, highlighting the agreement and suggesting future experimental improvements.

Contribution

It demonstrates the consistency of recent Sachs electric form factor data with hydrogen spectroscopy and theoretical predictions, and discusses potential for future experimental refinement.

Findings

Data aligns with theoretical predictions from chiral perturbation theory.

Current data is consistent with hydrogen spectroscopy measurements.

Future experiments can improve understanding of the form factor at low momentum transfer.

Abstract

Recently published data on the Sachs electric form factor by the PRad collaboration (Nature {\bf 575}, 147-151) are analyzed to investigate their consistency with the known proton charge radius from muonic and electronic hydrogen spectroscopy, as well as theoretical predictions from dispersively improved chiral perturbation theory. It is shown that the latter is fully consistent with the data, and pointers are given how future $e-p$ scattering experiments can lead to an improvement of our knowledge of the form factor in the low-momentum-transfer regime.