Proton size anomaly
High Energy Physics - Phenomenology
2011-04-12 v2 High Energy Physics - Experiment
Nuclear Experiment
Nuclear Theory
Abstract
A measurement of the Lamb shift in muonic hydrogen yields a charge radius of the proton that is smaller than the CODATA value by about 5 standard deviations. We explore the possibility that new scalar, pseudoscalar, vector, and tensor flavor-conserving nonuniversal interactions may be responsible for the discrepancy. We consider exotic particles that among leptons, couple preferentially to muons, and mediate an attractive nucleon-muon interaction. We find that the many constraints from low energy data disfavor new spin-0, spin-1 and spin-2 particles as an explanation.
Keywords
Cite
@article{arxiv.1011.3519,
title = {Proton size anomaly},
author = {Vernon Barger and Cheng-Wei Chiang and Wai-Yee Keung and Danny Marfatia},
journal= {arXiv preprint arXiv:1011.3519},
year = {2011}
}
Comments
4 pages, 2 figures. Version to appear in PRL