Speaker
Prof.
John Ralston
(University of Kansas)
Description
The proton charge radius measured in muonic hydrogen disagrees with other experiments by as much as seven standard deviations. However the “7σ” measure comes only from electronic hydrogen spectroscopy combined with many other data published by a single group. We perform an independent data analysis of the hydrogen spectrum that finds the charge radius rp = 0.87 ± 0.01. This result revises the discrepancy to 2.5-3.5 standard deviations, while also suggesting that electron scattering data is even more important than previously believed. Previous hydrogen analysis is found to be excessively sensitive to a single transition. The transition has a radically mismatched theoretical uncertainty, which is hundreds to thousands of times larger than its experimental uncertainty. The mismatched transition generates a “one-point fit” which by itself predicts the main features of previous analysis involving hundreds of free parameters. Rather than devise elaborate methods, we argue that high sensitivity should be avoided altogether in a scientifically conservative approach to resolving the proton size puzzle. We delete the hyper-sensitive transition as an “outlier”, obtaining the charge radius as well as the Rydberg constant R∞ = 1.097373156851 × 10^7 ± 8 × 10^−5m^−1. We recommend the proton size puzzle be confronted by comparing protons to protons with simple, transparent analysis, where the relation between procedural decisions, data, and theory inputs on the final outputs can readily be monitored.
Primary author
Prof.
John Ralston
(University of Kansas)
Co-author
John Martens
(University of Kansas)
