The helion charge radius from laser spectroscopy of muonic helium-3 ions

• 成果类型: Article
• 署名作者: Schuhmann, Karsten; Fernandes, Luis M. P.; Nez, Francois; Abdou Ahmed, Marwan; Amaro, Fernando D.; Amaro, Pedro; Biraben, Francois; Chen, Tzu-Ling; Covita, Daniel S.; Dax, Andreas J.; Diepold, Marc; Franke, Beatrice; Galtier, Sandrine; Gouvea, Andrea L.; Goetzfried, Johannes; Graf, Thomas; Haensch, Theodor W.; Hildebrandt, Malte; Indelicato, Paul; Julien, Lucile; Kirch, Klaus; Knecht, Andreas; Kottmann, Franz; Krauth, Julian J.; Liu, Yi-Wei; Machado, Jorge; Monteiro, Cristina M. B.; Mulhauser, Francoise; Naar, Boris; Nebel, Tobias; dos Santos, Joaquim M. F.; Santos, Jose Paulo; Szabo, Csilla I.; Taqqu, David; Veloso, Joao F. C. A.; Voss, Andreas; Weichelt, Birgit; Antognini, Aldo; Pohl, Randolf; CREMA Collaboration
• 署名单位: Swiss Federal Institutes of Technology Domain; ETH Zurich; Universidade de Coimbra; Universite PSL; College de France; Ecole Normale Superieure (ENS); Centre National de la Recherche Scientifique (CNRS); Sorbonne Universite; University of Stuttgart; Universidade Nova de Lisboa; National Tsing Hua University; Universidade de Aveiro; Max Planck Society; University of Munich; Johannes Gutenberg University of Mainz
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-12591
• DOI: 10.1126/science.adj2610
• 发表日期: 2025-05-22
• 页码: 854-858
• 关键词: proton structure; lamb shift; alpha

摘要

Hydrogen-like light muonic ions, in which one negative muon replaces all of the electrons, are extremely sensitive probes of nuclear structure. Using pulsed laser spectroscopy, we have measured three 2S-2P transitions in the muonic helium-3 (mu He-3(+)) ion, an ion formed by a negative muon and bare helium-3 nucleus. This allowed us to extract the Lamb shift, the 2P fine structure splitting, and the 2S-hyperfine splitting in mu He-3(+). Comparing these measurements with theory, we determined the root-mean-square charge radius of the helion (He-3 nucleus) to be r(h) = 1.97007(94) fm, in good agreement with the value from elastic electron scattering but a factor 15 more accurate. Our results represent benchmarks for few-nucleon theories and open the way for precision quantum electrodynamics tests in He atoms and ions.