The OPERA experiment

The OPERA experiment is a long baseline experiment designed to be the conclusive test of the νμ→ντ oscillation hypothesis by means of the direct observation of ντ in an initially pure νμ beam. The detector is located at the underground Gran Sasso laboratory, 730 km from CERN, on the CNGS neutrino beam and consists of a lead/emulsion film target complemented by electronic detectors. The physics motivations and the experimental technique will be reviewed. A summary of the performances will be given and the first sample of CNGS neutrino events, collected in August 2006, will be presented and discussed.