Tau Neutrino
On 31 May 2010, OPERA researchers observed the first tau neutrino candidate event in a muon neutrino beam. On 6 June 2012, OPERA announced the observation of a second tau neutrino event. On 26 March 2013, the experiment caught for the third time a muon neutrino oscillating into a tau neutrino during travel from CERN to LNGS.
Read more about this topic: OPERA Experiment