OPERA: waiting for the tau

TL;DR

The OPERA experiment aims to directly observe tau neutrinos resulting from muon neutrino oscillations using a high-granularity detector, with recent long-term data collection and analysis efforts to identify tau events.

Contribution

This paper details the design, operation, and initial results of the OPERA experiment, highlighting its novel approach to detecting tau neutrinos via nuclear emulsions.

Findings

First long physics run with 150 days of data collection

Operational at 1.35 kton target mass for tau appearance detection

Progress in data handling and nuclear emulsion analysis techniques

Abstract

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.