MEASUREMENT OF ANTIPROTON MAGNETIC-MOMENT AND MASS

We report a reanalysis of our p̄ x-ray data from Pb and U for fine-structure splitting and have included perturbations to the p̄-atomic energy levels arising from radiative corrections, relativistic effects, electron screening, finite nuclear size, and nuclear recoil. The value for the antiproton magnetic moment is -2.817 ± 0.048 nuclear magnetons which is 0.1% lower than our previous result and in agreement with the CPT prediction of -2.793. In addition we have obtained a value for the p̄ mass from the measured p̄-Pb x-ray transition energies from n=15 to n=10 The resulting mass 938.30 ± 0.13 MeV is in good agreement with the CPT prediction that the p̄ mass should equal the proton mass. We find mp-mp̄=-0. 02±0.13 MeV. © 1978 The American Physical Society.