The Proton Radius Puzzle
High Energy Physics - Phenomenology
2015-05-20 v1 Atomic Physics
Abstract
The proton size, specifically its charge radius, was thought known to about 1% accuracy. Now a new method probing the proton with muons instead of electrons finds a radius about 4% smaller, and to boot gives an uncertainty limit of about 0.1%. We review the different measurements, some of the calculations that underlie them, some of the suggestions that have been made to resolve the conflict, and give a brief overview new related experimental initiatives. At present, however, the resolution to the problem remains unknown.
Keywords
Cite
@article{arxiv.1502.05314,
title = {The Proton Radius Puzzle},
author = {Carl E. Carlson},
journal= {arXiv preprint arXiv:1502.05314},
year = {2015}
}
Comments
Accepted invited review for Progress in Particle and Nuclear Physics. 28 pages, 15 figures