Experimentelle Suche nach Myonneutrino-Oszillationen und Analyse der gleichzeitigen Mischung von drei Neutrinoflavours

In the present thesis the experiment of the CDHS collaboration on the search for inclusive muon-neutrino oscillations is described. The event rates of νμ reactions via charged currents was simultaneously measured in two detectors which were 130 m and 885 m away from the beam origin. The data contain no hints for oscillation effects. At maximal mixing mass differences of the contributing eigenstates are excluded in a range 0.26 ≤ Δm2 ≤ 90 eV2 with 90% confidence. The best sensitivity was reached for Δm2=2.5 eV2 and allows there a maximal mixing parameter sin22 ≤ 0.053. From the CDHS data the hitherto best limits on oscillation parameters resulted. From a common analysis of different oscillation experiments the allowed parameters for the case of simultaneous transitions between electron, muon, and tau neutrinos could be obtained. Regarding systematic uncertainties also here no evidence for oscillations exists. (orig./HSI)