Positronium and muonium, being purely leptonic, are very interesting systems to test bound state QED free of finite size effects and hadronic corrections [1]. They are also very sensitive probes to search for New Physics [2] and can be used to extract fundamental constants such as the muon mass and magnetic moment [3].
In this talk, we report the current status of the ongoing experiment...
Present status of tests of QED with highly charged ions is discussed.
The high-precision calculations of the Lamb shift, hyperfine splitting,
and bound-electron g factor are compared with the corresponding experimental
data. The calculations of the electron-positron pair-creation probabilities in low-energy heavy-ion collisions are considered. Special attention is focused on tests of QED at...
Our experimental group, MuSEUM (Muonium Spectroscopy Experiment Using Microwave), has been doing a precise spectroscopy of muonium ground state hyperfine splitting (MuHFS) with high-intensity pulsed muon beam supplied from J-PARC. We aim ten-fold improvement of the preceding measurement of the experimental value of MuHFS both at zero magnetic field and in high magnetic field (1.7 T). Muonium...
The ultra-precise determination of the g-factor of highly charged ions is a unique possibility to test the validity of the Standard Model, particularly Quantum Electrodynamics (QED) in extreme electric fields up to 1016 V/cm. While the weak-field regime has been exquisitely tested, in the presence of strong fields higher-order contributions beyond the Standard Model might become...
