The COSMOS experiment at  Searches for Neutrino Oscillations  The KARMEN experiment

The CERN experimental programme on neutrino oscillations

Two experiments, CHORUS and NOMAD, are presently taking data in the wide-band neutrino beam from the 450 GeV SPS with the aim of detecting $\nu_{\mu} - \nu_{\tau}$ oscillations. The method adopted by both experiments consists in detecting $\tau^{-}$ production with a sensitivity corresponding to a $\nu_{\tau}/\nu_{\mu}$ ratio of $\sim 2 \times 10^{-4}$.
 
    CHORUS aims at detecting the characteristic decay of the short-lived $\tau$ lepton in nuclear emulsion. It started data taking in May 1994. At the end of October 1995 the emulsion target was removed and developed (the measuring capability amounts to $\sim$ 200,000 events/year). New emulsion stacks are presently exposed to the neutrino beam for an additional two-year run.

    NOMAD aims at identifying $\tau^{-}$ production and decay using only kinematical criteria.

    Data have been recorded since May 1995 with a reduced target mass; data taking in parallel with CHORUS is scheduled until the end of 1997.

    The NOMAD experiment aims at detecting $\tau^{-}$ production by observing both leptonic and hadronic decay modes of the $\tau^{-}$.

    Recently, both CHORUS and NOMAD have presented preliminary results on $\nu_{\mu} - \nu_{\tau}$ available oscillations based on a small fraction of the data, which exclude $\nu_{\mu} - \nu_{\tau}$ oscillations with mixing angle $sin^{2} {2\theta} > 0.005$ for large $\Delta m^2$. NOMAD has also presented the results from a search for $\nu_{\mu} -\nu_{e}$ oscillations which excludes the $\Delta m ^{2} > 10 eV^{2}$ region of oscillation parameters suggested by LSND.