Measuring the α-particle charge radius with muonic helium-4 ions
Julian Krauth
(1, 2, 3)
,
Karsten Schuhmann
(4, 5)
,
Marwan Abdou Ahmed
(6)
,
Fernando Amaro
(7)
,
Pedro Amaro
(8)
,
François Biraben
(9)
,
Tzu-Ling Chen
(10)
,
Daniel Covita
(11)
,
Andreas Dax
(5)
,
Marc Diepold
(2)
,
Luis Fernandes
(7)
,
Beatrice Franke
(12, 2)
,
Sandrine Galtier
(13, 9)
,
Andrea Gouvea
(7)
,
Johannes Götzfried
(2)
,
Thomas Graf
(6)
,
Theodor Hänsch
(2, 14)
,
Jens Hartmann
(14)
,
Malte Hildebrandt
(5)
,
Paul Indelicato
(9)
,
Lucile Julien
(9)
,
Klaus Kirch
(4, 5)
,
Andreas Knecht
(5)
,
Yi-Wei Liu
(10)
,
Jorge Machado
(8)
,
Cristina Monteiro
(7)
,
Françoise Mulhauser
(2)
,
Boris Naar
(5)
,
Tobias Nebel
(2)
,
François Nez
(9)
,
Joaquim dos Santos
(7)
,
José Paulo Santos
(8)
,
Csilla Szabo
(15, 9)
,
David Taqqu
(4, 5)
,
João Veloso
(11)
,
Jan Vogelsang
(16, 2)
,
Andreas Voss
(6)
,
Birgit Weichelt
(6)
,
Randolf Pohl
(2, 3)
,
Aldo Antognini
(4, 5)
,
Franz Kottmann
(4, 5)
1
LaserLaB -
LaserLaB Vrije Universiteit Amsterdam
2 Max-Planck-Institute for Quantum Optics
3 Institut für Physik [Mainz]
4 IPA - Institute for Particle Physics and Astrophysics [ETH Zürich]
5 PSI - Paul Scherrer Institute
6 Institut für Strahlwerkzeuge
7 Department of Physics [Coimbra]
8 NOVA - Universidade Nova de Lisboa = NOVA University Lisbon
9 LKB [Collège de France] - Laboratoire Kastler Brossel
10 NTHU - National Tsing Hua University [Hsinchu]
11 Universidade de Aveiro
12 TRIUMF [Vancouver]
13 iLM - ATMOS - iLM - Atmosphère, Optique et Spectroscopie
14 LMU - Ludwig Maximilian University [Munich] = Ludwig Maximilians Universität München
15 Theiss Research
16 Skane University Hospital [Lund]
2 Max-Planck-Institute for Quantum Optics
3 Institut für Physik [Mainz]
4 IPA - Institute for Particle Physics and Astrophysics [ETH Zürich]
5 PSI - Paul Scherrer Institute
6 Institut für Strahlwerkzeuge
7 Department of Physics [Coimbra]
8 NOVA - Universidade Nova de Lisboa = NOVA University Lisbon
9 LKB [Collège de France] - Laboratoire Kastler Brossel
10 NTHU - National Tsing Hua University [Hsinchu]
11 Universidade de Aveiro
12 TRIUMF [Vancouver]
13 iLM - ATMOS - iLM - Atmosphère, Optique et Spectroscopie
14 LMU - Ludwig Maximilian University [Munich] = Ludwig Maximilians Universität München
15 Theiss Research
16 Skane University Hospital [Lund]
Sandrine Galtier
- Fonction : Auteur
- PersonId : 749701
- IdHAL : sandrine-galtier
- ORCID : 0000-0001-8153-102X
Jens Hartmann
- Fonction : Auteur
- PersonId : 783803
- ORCID : 0000-0003-1878-9321
Paul Indelicato
- Fonction : Auteur
- PersonId : 17063
- IdHAL : paul-indelicato
- ORCID : 0000-0003-4668-8958
- IdRef : 083262369
François Nez
- Fonction : Auteur
- PersonId : 739031
- IdHAL : francois-nez
- ORCID : 0000-0002-3478-7521
- IdRef : 161272991
Andreas Voss
- Fonction : Auteur
- PersonId : 763792
- ORCID : 0000-0002-4499-3660
- IdRef : 243123817
Résumé
The energy levels of hydrogen-like atomic systems can be calculated with great precision. Starting from their quantum mechanical solution, they have been refined over the years to include the electron spin, the relativistic and quantum field effects, and tiny energy shifts related to the complex structure of the nucleus. These energy shifts caused by the nuclear structure are vastly magnified in hydrogen-like systems formed by a negative muon and a nucleus, so spectroscopy of these muonic ions can be used to investigate the nuclear structure with high precision. Here we present the measurement of two 2S–2P transitions in the muonic helium-4 ion that yields a precise determination of the root-mean-square charge radius of the α particle of 1.67824(83) femtometres. This determination from atomic spectroscopy is in excellent agreement with the value from electron scattering, but a factor of 4.8 more precise, providing a benchmark for few-nucleon theories, lattice quantum chromodynamics and electron scattering. This agreement also constrains several beyond-standard-model theories proposed to explain the proton-radius puzzle, in line with recent determinations of the proton charge radius, and establishes spectroscopy of light muonic atoms and ions as a precise tool for studies of nuclear properties.
Origine : Publication financée par une institution