The proton radius puzzle
physics.atom-ph
/ Authors
J. J. Krauth, K. Schuhmann, M. Abdou Ahmed, F. D. Amaro, P. Amaro, F. Biraben, J. M. R. Cardoso, M. L. Carvalho, D. S. Covita, A. Dax
and 42 more authors
S. Dhawan, M. Diepold, L. M. P. Fernandes, B. Franke, S. Galtier, A. Giesen, A. L. Gouvea, J. Götzfried, T. Graf, M. Guerra, J. Haack, T. W. Hänsch, M. Hildebrandt, P. Indelicato, L. Julien, K. Kirch, A. Knecht, P. Knowles, F. Kottmann, E. -O. Le Bigot, Y. -W. Liu, J. A. M. Lopes, L. Ludhova, J. Machado
/ Abstract
High-precision measurements of the proton radius from laser spectroscopy of muonic hydrogen demonstrated up to six standard deviations smaller values than obtained from electron-proton scattering and hydrogen spectroscopy. The status of this discrepancy, which is known as the proton radius puzzle will be discussed in this paper, complemented with the new insights obtained from spectroscopy of muonic deuterium.