Discovery of tau neutrino appearance in the CNGS neutrino beam with the OPERA experiment

Understand

The OPERA experiment was designed to search for $\nu_{\mu} \rightarrow \nu_{\tau}$ oscillations in appearance mode, i.e.

• by detecting the $\tau$-leptons produced in charged current $\nu_{\tau}$ interactions.
• The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam.
• The observation of $\nu_{\mu} \rightarrow \nu_{\tau}$ appearance, achieved with four candidate events in a sub-sample of the data, was previously reported.