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Proton structure from the measurement of 2S-2P transition frequencies of muonic hydrogen.
- Source :
-
Science (New York, N.Y.) [Science] 2013 Jan 25; Vol. 339 (6118), pp. 417-20. - Publication Year :
- 2013
-
Abstract
- 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. These radii may be extracted from the laser spectroscopy of muonic hydrogen (μp, that is, a proton orbited by a muon). We measured the 2S(1/2)(F=0)-2P(3/2)(F=1) transition frequency in μp to be 54611.16(1.05) gigahertz (numbers in parentheses indicate one standard deviation of uncertainty) and reevaluated the 2S(1/2)(F=1)-2P(3/2)(F=2) transition frequency, yielding 49881.35(65) gigahertz. From the measurements, we determined the Zemach radius, r(Z) = 1.082(37) femtometers, and the magnetic radius, r(M) = 0.87(6) femtometer, of the proton. We also extracted the charge radius, r(E) = 0.84087(39) femtometer, with an order of magnitude more precision than the 2010-CODATA value and at 7σ variance with respect to it, thus reinforcing the proton radius puzzle.
Details
- Language :
- English
- ISSN :
- 1095-9203
- Volume :
- 339
- Issue :
- 6118
- Database :
- MEDLINE
- Journal :
- Science (New York, N.Y.)
- Publication Type :
- Academic Journal
- Accession number :
- 23349284
- Full Text :
- https://doi.org/10.1126/science.1230016