Experimental situation of beauty oscillations

The experimental situation of the evidences for beauty oscillations is reviewed. After a brief description of the formalism the results from the CERN proton-antiproton collider are described and compared with the results from electron-positron colliders. Whereas the experiments on the continuum measure a mixture of χs and χd the experiments on the Υ (4s) are only sensitive to χd. A forecast for 1992 is given and a method is described which allows to measure χs. A precision measurement of χs would allow to further constrain the CKM matrix and would eventually lead to a determination of the phase in the matrix