First results from the NOMAD experiment at CERN: search for $\nu_{\mu}\to\nu_{\tau}$ oscillations

NOMAD is a neutrino oscillation experiment designed to search for vT appearance in the CERN-SPS wide band predominantly v,,. beam. Signal detection is based on the identification of vT charged current interactions with the help of kinematic criteria. After the completion of the detector in August, 1995 the experiment has been successfully taking data till the end of 1996. The detector performances are in good agreement with our expectations. Preliminary analysis based on the 1995 data sample allows NOMAD to achieve the limit of 4 x 10-3 on sin2 28µ.T for large Ll.m2. NOMAD will continue to run during 1997. If no evidence for oscillations is found in all the NOMAD data the sensitivity to the oscillation parameters is expected to be improved by an order of magnitude with respect to the current limit.