Discovery of Tau Neutrino Appearance and Recent Results from OPERA

TL;DR

The OPERA experiment successfully observed tau neutrino appearance confirming neutrino oscillations over a 730 km baseline, utilizing advanced emulsion detection technology to identify five tau neutrino events and measure oscillation parameters.

Contribution

This paper reports the first observation of tau neutrino appearance in a long-baseline experiment using novel emulsion analysis technology.

Findings

Detection of five tau neutrino candidates

Rejection of background-only hypothesis at 5.1 sigma

Measurement and constraint of oscillation parameters

Abstract

The OPERA experiment was designed to observe ${\nu_{\mu}}$ ${\rightarrow}$ ${\nu_{\tau}}$ oscillations through ${\nu_{\tau}}$ appearance at a baseline of 730 km in the CNGS beam. Newly developed emulsion analysis technology allows to measure ${\nu_e}$, ${\nu_{\mu}}$ and ${\nu_{\tau}}$ interactions with the largest emulsion detector ever made. OPERA has detected five ${\nu_{\tau}}$ candidates, allowing to reject the background-only hypothesis at 5.1 ${\sigma}$. The parameters for standard and non-standard oscillations are measured and constrained.