Chorus and Nomad results

Considerations based on particle physics (in particular the so-called see-saw mechanism) and on cosmology, in relation to the Dark Matter question, motivated the search for numu nutau oscillation in the region of small mixing angles. We present here the outcome of the short-baseline programme carried out at CERN by the CHORUS and NOMAD experiments. Both experiments are about to publish their final results. At values of squared mass difference greater than 1 eV2 oscillations between numu and nutau are excluded at 90% C.L. down to mixing angles values of O(10^{-4}).