Emulsion data for neutrino tau appearance studies

The reconstructed tracks include hadrons, nuclear fragments moving both forward and backward and electron pairs, muon and tau leptons.</p><p>For this tau neutrino data sample, the Collaboration performed a dedicated analysis, with a detailed classification of all particles produced at the neutrino interaction. Indeed, in a neutrino interaction with the nucleons of the lead target, different hadrons are produced: the so-called shower hadrons and nuclear fragments produced in the break-up and in the evaporation of the target nucleus.

Moreover, according to the flavour of the interacting neutrino, a corresponding lepton is produced. After a flight length of about 1 mm, the tau lepton produced in the interaction of tau neutrinos decays into one of the following channels: single hadron (49.5%), electron (17.8%), muon (17.7%) and three hadrons (15.0%).</p><p>The tau neutrino candidate events are also <a href="/search?page=1&size=20&q=title%3A%22opera%20tau%20neutrino%20candidate%20event%22">described separately</a>.</p>