The OPERA experiment has been designed to perform the most
straightforward test of the phenomenon of neutrino oscillations. This
experiment exploits the CNGS high-intensity and high-energy beam of
muon neutrinos produced at the CERN SPS in Geneva pointing towards the
LNGS underground laboratory at Gran Sasso, 730 km away in central
Italy. OPERA is located in the Hall C of LNGS and it is aimed at
detecting for the first time the appearance of tau-neutrinos from the
transmutation (oscillation) of muon-neutrinos during their 3
millisecond travel from Geneva to Gran Sasso. In OPERA, tau-leptons
resulting from the interaction of tau-neutrinos will be observed in
"bricks" of photographic emulsion films interleaved with lead plates.
The apparatus contains about 150000 of such bricks for a total mass of
1300 tons and is complemented by electronic detectors (trackers and
spectrometers) and ancillary infrastructure. Its construction has been
completed in spring 2008 and the experiment is currently in data taking.

See "News and Updates" for the OPERA neutrino tau analysis