Measurement of the transition frequency from 2S1/2, F = 0 to 2P1/2, F = 1 states in Muonium

• Published in: Nature communications 2022-11, Vol.13 (1), p.7273-7273, Article 7273
• Main Authors: Janka, Gianluca, Ohayon, Ben, Cortinovis, Irene, Burkley, Zak, de Sousa Borges, Lucas, Depero, Emilio, Golovizin, Artem, Ni, Xiaojie, Salman, Zaher, Suter, Andreas, Prokscha, Thomas, Crivelli, Paolo
• Format: Article
• Language: English
• Subjects: 639/766/36/1123; 639/766/419/1131; Bosons; Expected values; Humanities and Social Sciences; Hydrogen; Hyperfine structure; multidisciplinary; Muonium; Muons; Physics; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-34672-0

Muons are puzzling physicists since their discovery when they were first thought to be the meson predicted by Yukawa to mediate the strong force. The recent result at Fermilab on the muon g-2 anomaly puts the muonic sector once more under the spotlight and calls for further measurements with this particle. Here, we present the results of the measurement of the 2 S 1/2 , F  = 0 → 2 P 1/2 ,  F  = 1 transition in Muonium. The measured value of 580.6(6.8) MHz is in agreement with the theoretical calculations. A value of the Lamb shift of 1045.5(6.8) MHz is extracted, compatible with previous experiments. We also determine the 2 S hyperfine splitting in Muonium to be 559.6(7.2) MHz. The measured transition being isolated from the other hyperfine levels holds the promise to provide an improved determination of the Muonium Lamb shift at a level where bound state QED recoil corrections not accessible in hydrogen could be tested. This result would be sensitive to new physics in the muonic sector, e.g., to new bosons which might provide an explanation of the g-2 muon anomaly and allow to test Lorentz and CPT violation. We also present the observation of Muonium in the n  = 3 excited state opening up the possibility of additional precise microwave measurements. Muonium is a hydrogen like bound system with a positive muon and an electron. Here the authors measure the Lamb shift and frequency of the transition from 2S1/2, F = 0 state to 2P1/2, F = 1 state in muonium atom and the hyperfine structure of the 2S level.