Messung des magnetischen Momentes des Antiprotons und eine Bestimmung des LS-Terms der Antiproton-Kern-Wechselwirkung

The new developed storage ring LEAR at CERN with its intensive antiproton beam allows for the first time high precision experiments with antiprotons at low energies. Among these experiments there are measurements on antiprotonic atoms to increase the statistics of the up to now existing poor data. From the investigation of those atoms one gets information about the particle properties of the antiproton, the properties of the nucleus and about the antiproton-nucleus-interaction. The subjects of this thesis are a measurement of the antiproton magnetic moment, a particle property, with the aim of testing the CPT-theorem for the strong interaction and the investigation of a possible spin-orbit-term of the p-nucleus-interaction. For both aspects the information is given in the finestructure-splitting of antiprotonic x-ray-transitions from heavy nuclei, since only for those the splitting is observable. From the finestructure-splitting of the transition 11-+ 10 in 208Pb the magnetic moment of the antiproton can be calculated. The result of this best measurement up to now is μ.P = ( - 2.8007 ± 0.0091 ) μN In between the error bars it confirms the CPT-Theorem and the new average value for the difference of the antiproton magnetic moment from the proton magnetic moment is (μp - μp)/average = (-2.5±3)·10-3 At the same time the limits of our detectors are described and other possiblities are discussed. In 174Yb one observes a splitting of the last observable transition 9 .... 8, which is influenced by the strong interaction. From our measurement we find that the measured splitting is different from the calculated electromagnetic value and the Lorentz-widths of both line components are different as well. It is LiE5W = 58± 25 ± 13 eV and AT = 195 ± 58 ± 20 eV As result we find a sign for the existence of a spin-orbit-term of the antiproton-nucleus-interaction. Nevertheless it has to be confirmed in further experiments. Different theoretical models up to now do not agree with each other. Furthermore they are just valid for light nuclei. A determination of the LS-term of the elementary p-nucleon-interaction from our results, doing a microscopic calculation, is difficult, since one has to know very precisely the properties of the measured nuleus.