# Proton rms-radii from low-q power expansions?

## TL;DR

This paper critiques recent claims that low-q electron scattering data analyses yield proton charge radii consistent with muonic hydrogen measurements, explaining why those claims are incorrect.

## Contribution

It clarifies the errors in previous low-q analysis methods that led to underestimated proton radii.

## Key findings

- Low-q analyses do not produce the smaller radii claimed by recent publications.
- Full data set analyses still support larger proton radii consistent with previous measurements.
- The paper identifies methodological errors in low-q radius extraction.

## Abstract

Several recent publications claim that the proton charge {\em rms}-radius resulting from the analysis of electron scattering data restricted to {\em low} momentum transfer agrees with the radius determined from muonic hydrogen, in contrast to the radius resulting from analyses of the full (e,e) data set which is $0.04fm$ larger. Here we show why these publications erroneously arrive at the low radii.