# A measurement of the atomic hydrogen Lamb shift and the proton charge radius

@article{Bezginov2019AMO,
title={A measurement of the atomic hydrogen Lamb shift and the proton charge radius},
author={N Bezginov and Travis Valdez and Marko Horbatsch and A Marsman and Amar C Vutha and E A Hessels},
journal={Science},
year={2019},
volume={365},
pages={1007 - 1012}
}
Unraveling the proton puzzle The discrepancy between the proton size deduced from the Lamb shift in muonic hydrogen and the average, textbook value based on regular (electronic) hydrogen has puzzled physicists for nearly a decade. One possible resolution could be that electrons interact with protons in a different way than muons do, which would require “new physics.” Bezginov et al. measured the Lamb shift in electronic hydrogen, which allowed for a direct comparison to the Lamb shift measured…

## Topics from this paper

The proton size
• Physics
• 2020
The proton charge radius has been measured since the 1950s using elastic electron–proton scattering and ordinary hydrogen atomic spectroscopy. In 2010, a highly precise measurement of the proton
Proton Radius from Muonic Hydrogen Spectroscopy and Effect of Atomic Nucleus Motion
• Physics
• 2021
The proton radius has been measured in electron-proton scattering experiments and laser based spectroscopy of muonic hydrogen. The latter method is based on the precise calculations for the atomic
THE QUEST FOR THE PROTON CHARGE RADIUS
A slight anomaly in optical spectra of the hydrogen atom led Willis E. Lamb to the search for the proton size. As a result, he found the shift of the 2S1/2 level, the first experimental demonstration
Transverse charge density and the radius of the proton
• Physics
• 2021
A puzzling discrepancy exists between the values of the proton charge radius obtained using different experimental techniques: elastic electron-proton scattering and spectroscopy of electronic and
A High Precision Measurement of the Proton Charge Radius at JLab
The elastic electron-proton ($e-p$) scattering and the spectroscopy of hydrogen atoms are the two traditional methods to determine the proton charge radius ($r_{p}$). In 2010, a new method using the
Measuring the α-particle charge radius with muonic helium-4 ions
The measurement of two 2S–2P transitions in the muonic helium-4 ion yields a precise determination of the root-mean-square charge radius of the α particle, providing a benchmark for few-nucleon theories, lattice quantum chromodynamics and electron scattering.
Two-photon frequency comb spectroscopy of atomic hydrogen
Two-photon ultraviolet direct frequency comb spectroscopy on the 1S-3S transition in atomic hydrogen is performed to illuminate the so-called proton radius puzzle and to demonstrate the potential of this method.
Crisis and catharsis in atomic physics
Ginin et al. (2) report the precision measurement of the 1S-3S transition to help finally resolve the proton size puzzle.
The proton radius (puzzle?) and its relatives
• Physics
Progress in Particle and Nuclear Physics
• 2021
Proton-electron mass ratio from laser spectroscopy of HD+ at the part-per-trillion level
By leveraging high-precision ab initio calculations, the researchers converted their measurement to tight constraints on the proton-electron and deuteron-proton mass ratios, consistent with the most recent Penning trap determinations of these quantities.

## References

SHOWING 1-10 OF 24 REFERENCES
The Rydberg constant and proton size from atomic hydrogen
The authors obtained the size of the proton using very accurate spectroscopic measurements of regular hydrogen using an asymmetric fit function, which eliminates line shifts from quantum interference of neighboring atomic resonances.
Proton Structure from the Measurement of 2S-2P Transition Frequencies of Muonic Hydrogen
Accurate knowledge of the charge and Zemach radii of the proton is essential, not only for understanding its structure but also as input for tests of bound-state quantum electrodynamics and its predictions for the energy levels of hydrogen.
The size of the proton
The root-mean-square charge radius, rp, has been determined with an accuracy of 2 per cent by electron–proton scattering experiments, and the present most accurate value of rp (with an uncertainty of 1 per cent) is given by the CODATA compilation of physical constants.
Tabulation of the bound-state energies of atomic hydrogen
• Materials Science, Physics
• 2016
We present tables for the bound-state energies for atomic hydrogen. The tabulated energies include the hyperfine structure, and thus this work extends the work of Rev. Mod. Phys. {\bf 84}, 1527
Muonic Hydrogen and the Proton Radius Puzzle
• Physics
• 2013
The extremely precise extraction of the proton radius obtained by Pohl et al. from the measured energy difference between the 2P and 2S states of muonic hydrogen disagrees significantly with that
New Measurement of the 1S-3S Transition Frequency of Hydrogen: Contribution to the Proton Charge Radius Puzzle.
We present a new measurement of the 1S-3S two-photon transition frequency of hydrogen, realized with a continuous-wave excitation laser at 205 nm on a room-temperature atomic beam, with a relative
The Electromagnetic shift of energy levels
B very beautiful experiments, Lamb and Retherford1 have shown that the fine structure of the second quantum state of hydrogen does not agree with the prediction of the Dirac theory. The 2s level,
The quantum theory of the electron
The new quantum mechanics, when applied to the problem of the structure of the atom with point-charge electrons, does not give results in agreement with experiment. The discrepancies consist of
Polarization effects in the positron theory
Some of the consequences of the positron theory for the special case of impressed electrostatic fields are investigated. By imposing a restriction only on the maximum value of the field intensity,
Systematic effects important to separated-oscillatory-field measurements of the n=2 Lamb shift in atomic hydrogen
• Physics
Physical Review A
• 2018
We evaluate a number of systematic effects that are important for an experimental microwave measurement of the $n$$=$$2$ S-to-P intervals in atomic hydrogen. The analysis is important for both