High precision measurements of the ground state hyperfine structure interval of muonium and of the muon magnetic moment

No abstract

The muon anomalous magnetic moment has been measured in a new experiment at Brookhaven. Polarized muons were stored in a superferric ring, and the angular frequency difference, v a , between the spin precession and orbital frequencies was determined by measuring the time distribution of highenergy decay positrons. The ratio R of v a to the Larmor precession frequency of free protons, v p , in the storage-ring magnetic field was measured. We find R 3.707 220͑48͒ 3 10 23. With m m ͞m p 3.183 345 47͑47͒ this gives a m 1 1 165 925͑15͒ 3 10 29 (613 ppm), in good agreement with the previous CERN measurements for m 1 and m 2 and of approximately the same precision.

No abstract

We report the results of a measurement of the Lamb shift in the n =2 state of muonium. Muonium atoms in the metastable 2S state were produced by the beam-foil method and the formation rate was determined by observation of the Ly-a photons emitted when the metastable atoms were quenched in a static electric field. The Lamb shift (4'&") was measured through observation of the microwave-induced 2'S&&2-2'P&&2 transition with the result $&"=1042» MHz. This result is in agreement with the current theoretical value.