Portal de Periódicos da CAPES

Proton Structure from the Measurement of 2S-2P Transition Frequencies of Muonic Hydrogen

2013; American Association for the Advancement of Science; Volume: 339; Issue: 6118 Linguagem: Inglês

10.1126/science.1230016

1095-9203

Aldo Antognini, F. Nez, Karsten Schuhmann, F. D. Amaro, F. Biraben, J. M. R. Cardoso, D. S. Covita, A. Dax, S. Dhawan, Marc Diepold, L. M. P. Fernandes, Adolf Giesen, Andrea L. Gouvea, Thomas Graf, T. W. Hänsch, P. Indelicato, L. Julién, Cheng-Yang Kao, Paul Knowles, F. Kottmann, Éric-Olivier Le Bigot, Yiwei Liu, J. A. M. Lopes, L. Ludhová, C.M.B. Monteiro, F. Mulhauser, Tobias Nebel, Paul Rabinowitz, J.M.F. dos Santos, L. A. Schaller, Catherine Schwob, D. Taqqu, J.F.C.A. Veloso, Jan Vogelsang, Randolf Pohl,

Advanced Chemical Physics Studies

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.