The OPERA experiment at Gran Sasso

OPERA (Oscillation Project with Emulsion-tRacking Apparatus) is a long-baseline experiment to search for vμ → vτ oscillations in the Gran Sasso laboratory. It will study the interactions of 20 GeV neutrinos produced at CERN to search for neutrino flavour oscillation over a distance of about 730 Km. The OPERA detector is designed to unambiguously observe the appearance of vτ in a pure vμ beam. The detector is based on a massive lead/nuclear emulsion target. Nuclear emulsions are exploited for the direct observation of the decay of the τ lepton, produced in vτ charged-current interactions. The discovery potential of OPERA is ultimately due to a very low background level and could therefore play a decisive role in the clarification of the experimental scenario.