Anomalous magnetic moment of the muon and the ground-state hyperfine splitting of muonium

This paper describes the status of experiments to determine the anomalous magnetic moment of the muon and the ground-state hyperfine splitting of muonium. A muon precision storage ring superconducting magnet system is being constructed for our experiment to determine the muon g-2 value to 0.35 ppm. This experiment will be sensitive to the weak interaction contribution, thus providing a sensitive test of the standard model concerning the renormalizability of the electroweak theory. The data collection has begun for the new precision experiment to study the muonium hyperfine structure in its ground state. The resonance line narrowing by a factor of 2 has been observed in the magnetic field of 1.7 T using the old muonium method. A standard NMR probe has been constructed to obtain the NMR frequency for free protons to better than 0.05 ppm