Learning from tau appearance

Understand

The study of numu->nutau oscillation and the explicit observation of the nutau through the identification of the final-state tau lepton ("direct appearance search") represent the most straightforward test of the oscillation phenomenon.

• It is, nonetheless, the most challenging from the experimental point of view.
• In this paper we discuss the current empirical evidence for direct appearance of tau neutrinos at the atmospheric scale and the perspectives for the next few years, up to the completion of the CNGS physics programme.
• We investigate the relevance of this specific oscillation channel to gain insight into neutrino physics within the standard three-family framework.