Speaker
Prof.
Koichioro Shimomura
(KEK IMSS)
Description
High precision measurements of the ground state hyperfine structure (HFS)
of muonium, a leptonic system made of a bound state of a positive muon
with an electron, is a stringent tool for testing bound-state quantum
electrodynamics (QED) theory, determining fundamental constants of the
muon magnetic moment and mass, and searches for new physics. Muonium is
the most suitable system to test QED because both theoretical and
experimental values can be precisely determined.
At the J-PARC Muon Science Facility (MUSE), the MuSEUM collaboration is
planing complementary measurements of muonium HFS both at zero field and
at high magnetic field. The new high-intensity muon beam that will soon
be available at MUSE H-Line will provide an opportunity to improve the
precision of these measurements by one order of magnitude. The previous
measurements at zero field [1] and high field [2] were performed decades
ago at LAMPF with experimental uncertainties mostly dominated by
statistical errors. An overview of the different aspects of these new
muonium HFS measurements, the current status of the preparation for high
-field measurements, and the latest measurements at zero field will be
presented.
[1] D. E. Casperson et al., Physics Letters 59B (1975) 397.
[2] W. Liu et al., Physical Review Letters 82 (1999) 711.
Primary author
Prof.
Koichioro Shimomura
(KEK IMSS)
