More Results from the Opera Experiment at the Gran Sasso Underground Lab

Abstract

The OPERA experiment reached its main goal by proving the appearance of [Formula: see text] in the CNGS [Formula: see text] beam. Five [Formula: see text] candidates fulfilling the analysis defined in the proposal were detected with a S/B ratio of about ten allowing to reject the null hypothesis at 5.1[Formula: see text]. The search has been extended by loosening the selection criteria in order to obtain a statistically enhanced, lower purity, signal sample. One such interesting neutrino interaction with a double vertex topology having a high probability of being a [Formula: see text] interaction with charm production is reported. Based on the enlarged data sample the estimation of [Formula: see text][Formula: see text] in appearance mode is presented. The search for [Formula: see text] interactions has been extended over the full data set with a more than twofold increase in statistics with respect to published data. The analysis of the [Formula: see text] channel is updated and the implications of the electron neutrino sample in the framework of the 3+1 neutrino model is discussed. An analysis of [Formula: see text] interactions in the framework of the sterile neutrino model has also been performed. Finally, the results of the study of charged hadron multiplicity distributions is presented.