Proton Structure from the Measurement of 2S-2P Transition Frequencies of Muonic Hydrogen

TLDR

We have 5 labels present. Let's parse content. Lines: 1. [Purpose] Proton Still Too Small Despite a proton's tiny size, it is possible to measure its radius based on its charge or magnetization distributions. This sentence seems garbled: "Proton Still Too Small Despite a proton's tiny size, it is possible to measure its radius based on its charge or magnetization distributions." Might be the Purpose?

Abstract

Proton Still Too Small Despite a proton's tiny size, it is possible to measure its radius based on its charge or magnetization distributions. Traditional measurements of proton radius were based on the scattering between protons and electrons. Recently, a precision measurement of a line in the spectrum of muonium—an atom consisting of a proton and a muon, instead of an electron—revealed a radius inconsistent with that deduced from scattering studies. Antognini et al. (p. 417 ; see the Perspective by Margolis ) examined a different spectral line of muonium, with results less dependent on theoretical analyses, yet still inconsistent with the scattering result; in fact, the discrepancy increased.