Long baseline accelerator neutrino experiments: Present and future

A nu(mu) disappearance effect has been seen in atmospheric neutrino experiments. This has led to the "evidence for neutrino osciilations". The next problem in neutrino physics is to perform the right experiment(s) to elucidate in a comprehensive way the pattern of neutrino masses and mixings. The long baseline experiments will play a fundamental role at settling definitively the question of flavor oscillation and at measuring with good precision the oscillation parameters. The CERN-NGS beam coupled with the proposed ICANOE and OPERA detectors is the only programme capable of sensitive tau and electron appearance searches.