The size of the proton

Publication type:
Journal article
Metadata:
Autoren
  • Randolf Pohl
  • Aldo Antognini
  • Francois Nez
  • Fernando D Amaro
  • Francois Biraben
  • Joao MR Cardoso
  • Daniel S Covita
  • Andreas Dax
  • Satish Dhawan
  • Luis MP Fernandes
  • Adolf Giesen
  • Thomas Graf
  • Theodor W Haensch
  • Paul Indelicato
  • Lucile Julien
  • Cheng-Yang Kao
  • Paul Knowles
  • Eric-Olivier Le Bigot
  • Yi-Wei Liu
  • Jose AM Lopes
  • Livia Ludhova
  • Cristina MB Monteiro
  • Francoise Mulhauser
  • Tobias Nebel
  • Paul Rabinowitz
  • Joaquim MF dos Santos
  • Lukas A Schaller
  • Karsten Schuhmann
  • Catherine Schwob
  • David Taqqu
  • Joao FCA Veloso
  • Franz Kottmann
Autoren-URL
https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=fis-test-1&SrcAuth=WosAPI&KeyUT=WOS:000279580800031&DestLinkType=FullRecord&DestApp=WOS_CPL
DOI
10.1038/nature09250
Externe Identifier
  • Clarivate Analytics Document Solution ID: 621LR
  • PubMed Identifier: 20613837
ISSN
0028-0836
Ausgabe der Veröffentlichung
7303
Zeitschrift
NATURE
Paginierung
213 - 216
Datum der Veröffentlichung
2010
Status
Published
Titel
The size of the proton
Sub types
  • Article
Ausgabe der Zeitschrift
466

Data source: Web of Science (Lite)

Other metadata sources:
Autoren
  • Randolf Pohl
  • Aldo Antognini
  • François Nez
  • Fernando D Amaro
  • François Biraben
  • João MR Cardoso
  • Daniel S Covita
  • Andreas Dax
  • Satish Dhawan
  • Luis MP Fernandes
  • Adolf Giesen
  • Thomas Graf
  • Theodor W Hänsch
  • Paul Indelicato
  • Lucile Julien
  • Cheng-Yang Kao
  • Paul Knowles
  • Eric-Olivier Le Bigot
  • Yi-Wei Liu
  • José AM Lopes
  • Livia Ludhova
  • Cristina MB Monteiro
  • Françoise Mulhauser
  • Tobias Nebel
  • Paul Rabinowitz
  • Joaquim MF dos Santos
  • Lukas A Schaller
  • Karsten Schuhmann
  • Catherine Schwob
  • David Taqqu
  • João FCA Veloso
  • Franz Kottmann
DOI
10.1038/nature09250
eISSN
1476-4687
ISSN
0028-0836
Ausgabe der Veröffentlichung
7303
Zeitschrift
Nature
Sprache
en
Paginierung
213 - 216
Datum der Veröffentlichung
2010
Status
Published
Herausgeber
Springer Science and Business Media LLC
Herausgeber URL
http://dx.doi.org/10.1038/nature09250
Datum der Datenerfassung
2023
Titel
The size of the proton
Ausgabe der Zeitschrift
466

Data source: Crossref

Abstract
The proton is the primary building block of the visible Universe, but many of its properties-such as its charge radius and its anomalous magnetic moment-are not well understood. The root-mean-square charge radius, r(p), has been determined with an accuracy of 2 per cent (at best) by electron-proton scattering experiments. The present most accurate value of r(p) (with an uncertainty of 1 per cent) is given by the CODATA compilation of physical constants. This value is based mainly on precision spectroscopy of atomic hydrogen and calculations of bound-state quantum electrodynamics (QED; refs 8, 9). The accuracy of r(p) as deduced from electron-proton scattering limits the testing of bound-state QED in atomic hydrogen as well as the determination of the Rydberg constant (currently the most accurately measured fundamental physical constant). An attractive means to improve the accuracy in the measurement of r(p) is provided by muonic hydrogen (a proton orbited by a negative muon); its much smaller Bohr radius compared to ordinary atomic hydrogen causes enhancement of effects related to the finite size of the proton. In particular, the Lamb shift (the energy difference between the 2S(1/2) and 2P(1/2) states) is affected by as much as 2 per cent. Here we use pulsed laser spectroscopy to measure a muonic Lamb shift of 49,881.88(76) GHz. On the basis of present calculations of fine and hyperfine splittings and QED terms, we find r(p) = 0.84184(67) fm, which differs by 5.0 standard deviations from the CODATA value of 0.8768(69) fm. Our result implies that either the Rydberg constant has to be shifted by -110 kHz/c (4.9 standard deviations), or the calculations of the QED effects in atomic hydrogen or muonic hydrogen atoms are insufficient.
Addresses
  • Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany. randolf.pohl@mpq.mpg.de
Autoren
  • Randolf Pohl
  • Aldo Antognini
  • François Nez
  • Fernando D Amaro
  • François Biraben
  • João MR Cardoso
  • Daniel S Covita
  • Andreas Dax
  • Satish Dhawan
  • Luis MP Fernandes
  • Adolf Giesen
  • Thomas Graf
  • Theodor W Hänsch
  • Paul Indelicato
  • Lucile Julien
  • Cheng-Yang Kao
  • Paul Knowles
  • Eric-Olivier Le Bigot
  • Yi-Wei Liu
  • José AM Lopes
  • Livia Ludhova
  • Cristina MB Monteiro
  • Françoise Mulhauser
  • Tobias Nebel
  • Paul Rabinowitz
  • Joaquim MF Dos Santos
  • Lukas A Schaller
  • Karsten Schuhmann
  • Catherine Schwob
  • David Taqqu
  • João FCA Veloso
  • Franz Kottmann
DOI
10.1038/nature09250
eISSN
1476-4687
Externe Identifier
  • PubMed Identifier: 20613837
Open access
false
ISSN
0028-0836
Ausgabe der Veröffentlichung
7303
Zeitschrift
Nature
Sprache
eng
Medium
Print
Paginierung
213 - 216
Datum der Veröffentlichung
2010
Status
Published
Datum der Datenerfassung
2010
Titel
The size of the proton.
Sub types
  • Research Support, Non-U.S. Gov't
  • Journal Article
Ausgabe der Zeitschrift
466

Data source: Europe PubMed Central

Abstract
The proton is the primary building block of the visible Universe, but many of its properties-such as its charge radius and its anomalous magnetic moment-are not well understood. The root-mean-square charge radius, r(p), has been determined with an accuracy of 2 per cent (at best) by electron-proton scattering experiments. The present most accurate value of r(p) (with an uncertainty of 1 per cent) is given by the CODATA compilation of physical constants. This value is based mainly on precision spectroscopy of atomic hydrogen and calculations of bound-state quantum electrodynamics (QED; refs 8, 9). The accuracy of r(p) as deduced from electron-proton scattering limits the testing of bound-state QED in atomic hydrogen as well as the determination of the Rydberg constant (currently the most accurately measured fundamental physical constant). An attractive means to improve the accuracy in the measurement of r(p) is provided by muonic hydrogen (a proton orbited by a negative muon); its much smaller Bohr radius compared to ordinary atomic hydrogen causes enhancement of effects related to the finite size of the proton. In particular, the Lamb shift (the energy difference between the 2S(1/2) and 2P(1/2) states) is affected by as much as 2 per cent. Here we use pulsed laser spectroscopy to measure a muonic Lamb shift of 49,881.88(76) GHz. On the basis of present calculations of fine and hyperfine splittings and QED terms, we find r(p) = 0.84184(67) fm, which differs by 5.0 standard deviations from the CODATA value of 0.8768(69) fm. Our result implies that either the Rydberg constant has to be shifted by -110 kHz/c (4.9 standard deviations), or the calculations of the QED effects in atomic hydrogen or muonic hydrogen atoms are insufficient.
Date of acceptance
2010
Autoren
  • Randolf Pohl
  • Aldo Antognini
  • François Nez
  • Fernando D Amaro
  • François Biraben
  • João MR Cardoso
  • Daniel S Covita
  • Andreas Dax
  • Satish Dhawan
  • Luis MP Fernandes
  • Adolf Giesen
  • Thomas Graf
  • Theodor W Hänsch
  • Paul Indelicato
  • Lucile Julien
  • Cheng-Yang Kao
  • Paul Knowles
  • Eric-Olivier Le Bigot
  • Yi-Wei Liu
  • José AM Lopes
  • Livia Ludhova
  • Cristina MB Monteiro
  • Françoise Mulhauser
  • Tobias Nebel
  • Paul Rabinowitz
  • Joaquim MF Dos Santos
  • Lukas A Schaller
  • Karsten Schuhmann
  • Catherine Schwob
  • David Taqqu
  • João FCA Veloso
  • Franz Kottmann
Autoren-URL
https://www.ncbi.nlm.nih.gov/pubmed/20613837
DOI
10.1038/nature09250
eISSN
1476-4687
Ausgabe der Veröffentlichung
7303
Zeitschrift
Nature
Sprache
eng
Country
England
Paginierung
213 - 216
PII
nature09250
Datum der Veröffentlichung
2010
Status
Published
Datum, an dem der Datensatz öffentlich gemacht wurde
2010
Titel
The size of the proton.
Sub types
  • Journal Article
  • Research Support, Non-U.S. Gov't
Ausgabe der Zeitschrift
466

Data source: PubMed

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