OPERA: waiting for the tau
  The OPERA experiment, whose aim is the direct observation of nu_mu ~> nu_tau oscillations in appearance mode in the CNGS high-energy neutrino beam, consists of a high-granularity modular target of nuclear emulsions-lead "bricks", richly instrumented with electronic detectors necessary for the location of neutrino interactions and kinematic analysis. After the first short runs of August 2006, October 2006 and October 2007, the experiment started early this summer its first long physics run (about 150 days). Operating at the final target mass of 1.35 kton, the 2008 run can realistically offer the first chance to observe a tau originated from a flavour oscillated nu_mu. This contribution will discuss the different aspects of the experiment, the challenges of the data handling and the recent achievements. It will also outline the various steps required for the analysis in nuclear emulsions from the "brick finding" to the vertex reconstruction. 
Andrea Longhin (for the OPERA Collaboration)