Limits on muon-neutrino to tau-neutrino oscillations induced by a sterile neutrino state obtained by OPERA at the CNGS beam

TL;DR

This paper reports on OPERA's search for sterile neutrino effects by analyzing tau neutrino appearance data, setting limits on sterile neutrino mixing parameters within the context of muon to tau neutrino oscillations.

Contribution

It provides new constraints on sterile neutrino mixing parameters using OPERA's tau neutrino appearance data from the CNGS beam.

Findings

Four tau neutrino candidates detected, consistent with standard oscillations.

Derived limits on sterile neutrino mixing parameters.

Enhanced understanding of neutrino oscillation models.

Abstract

The OPERA experiment, exposed to the CERN to Gran Sasso $\nu_\mu$ beam, collected data from 2008 to 2012. Four oscillated $\nu_\tau$ Charged Current interaction candidates have been detected in appearance mode, which are consistent with $\nu_\mu \to \nu_\tau$ oscillations at the atmospheric $\Delta m^2$ within the "standard" three-neutrino framework. In this paper, the OPERA $\nu_\tau$ appearance results are used to derive limits on the mixing parameters of a massive sterile neutrino.