Update of Muonium 1S–2S transition frequency
Irene Cortinovis, Ben Ohayon, Lucas de Sousa Borges, Gianluca Janka, Artem Golovizin, N. O. Zhadnov, P. Crivelli
Abstract
Abstract We present an updated value of the Muonium 1 S –2 S transition frequency, highlighting contributions from different QED corrections as well as the large uncertainty in the Dirac contribution, stemming from the uncertainty of the electron to muon mass ratio. Improving the measurement of this spectral line would allow to extract a more accurate determination of fundamental constants, such as the electron to muon mass ratio or, combined with the Muonium hyperfine splitting, an independent value of the Rydberg constant. Furthermore, we report on the current status of the Mu-MASS experiment, which aims at measuring the Muonium 1 S –2 S transition frequency at a $$10\hbox {kHz}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>10</mml:mn> <mml:mtext>kHz</mml:mtext> </mml:mrow> </mml:math> uncertainty level. Graphic abstract