Search for the Oscillation $\nu _{\mu}$ $\rightarrow$ $\nu_{\tau}$

% WA96 \\ \\ The experiment searches for the oscillation $ {\nu} _{\mu} \rightarrow \nu _{\tau} $ in the CERN wide-band neutrino beam. It aims at detecting $ \nu _{\tau} $ charged current interactions by observing the production of the $\tau$ lepton through its various decay modes by means of kinematical criteria. \\ \\The detector reconstructs the events kinematics and identifies electrons, muons and photons. It uses the UA1 magnet. The target consists of 44~drift chambers, (132 sensitive planes) each 2.2~\% $ X ^{o} $ thick, with a total mass of 2.7 tons over a fiducial volume of 2.6~x~2.6 x 4 m$^3$. It is followed by transition radiation detectors, an electromagnetic calorimeter which includes a preshower detector and a hadronic calorimeter. Muons are identified after the return-yoke of the magnet by large-area drift chambers located behind the hadronic calorimeter and additional iron absorber.