Measurement of 2P-1S-transition energy in muon-barium atom
As a means of studying the nuclear charge radius, the 2P-- 1S-transition energy of the muon-barium-atom (mmmesonic K/sub alpha /-line) was measured. A 3" x 3" NaI-spectrometer was used at the muon channel of the CERN- synchrocyclotron. Since the muon intensity was high, measurements could be repeated under various conditions. Experiment, checks, and results are described. The 2P--1S-energy obtained, (3981 ction in DDT-C/ 30) kev, agrees with the value calculated by Ford and Wills (3974 kev) for a family II''-charge distribution fitted to the Stanford electron scattering data. (auth)