More results from the OPERA experiment

Abstract

The OPERA experiment reached its main goal by proving the appearance of tau-neutrinos in the CNGS muon-neutrino beam. A total sample of 5 candidates fulfilling the analysis defined in the proposal was detected with a S/B ratio of about ten allowing to reject the null hypothesis with a significance of 5.1 σ . The search was extended to ν τ -like interactions failing the kinematical analysis defined in the experiment proposal, to obtain a statistically enhanced, lower purity, signal sample. One such interesting neutrino interaction showing a double vertex topology with a high probability of being a tau-neutrino interaction with charm production will be reported. Based on the enlarged data sample the estimation of ∆m 2 23 in appearance mode will be presented and updated. The search for electron-neutrino interactions was extended over the full data set with a more than twofold increase in statistics with respect to published data. The analysis of the ν µ → ν e channel is updated and the implications of the electron-neutrino sample in the framework of the 3+1 sterile model is discussed. An analysis of the ν µ → ν τ oscillations in the framework of the sterile neutrino model was also performed. Finally, the analysis of the annual modulation of atmospheric muons will be discussed. XVII International Workshop on Neutrino Telescopes