The OPERA experiment in the CERN-Gran Sasso neutrino beam

Summary form only given. Recent results from atmospheric neutrino experiments show evidence for neutrino oscillations and hence the existence of a non-vanishing neutrino mass. These results are based on the observations of a lower number of upgoing atmospheric muon neutrinos with respect to the predictions, and on the distortion of the shape of the neutrino angular distribution. These observations have been interpreted in terms of nu /sub mu / to nu /sub tau / oscillations. (1 refs).