Final results of the OPERA experiment on $ν_τ$ appearance in the CNGS beam
Creators: name: OPERA Collaboration
name: Agafonova, N.
name: Alexandrov, A.
name: Anokhina, A.
name: Aoki, S.
name: Ariga, A.
name: Ariga, T.
name: Bertolin, A.
name: Bozza, C.
name: Brugnera, R.
name: Buonaura, A.
name: Buontempo, S.
name: Chernyavskiy, M.
name: Chukanov, A.
name: Consiglio, L.
name: D'Ambrosio, N.
name: De Lellis, G.
name: De Serio, M.
name: Sanchez, P. del Amo
name: Di Crescenzo, A.
name: Di Ferdinando, D.
name: Di Marco, N.
name: Dmitrievsky, S.
name: Dracos, M.
name: Duchesneau, D.
name: Dusini, S.
name: Dzhatdoev, T.
name: Ebert, J.
name: Ereditato, A.
name: Favier, J.
name: Fini, R. A.
name: Fornari, F.
name: Fukuda, T.
name: Galati, G.
name: Garfagnini, A.
name: Gentile, V.
name: Goldberg, J.
name: Gornushkin, Y.
name: Gorbunov, S.
name: Grella, G.
name: Guler, A. M.
name: Gustavino, C.
name: Hagner, C.
name: Hara, T.
name: Hayakawa, T.
name: Hollnagel, A.
name: Ishiguro, K.
name: Iuliano, A.
name: Jakovcic, K.
name: Jollet, C.
name: Kamiscioglu, C.
name: Kamiscioglu, M.
name: Kim, S. H.
name: Kitagawa, N.
name: Klicek, B.
name: Kodama, K.
name: Komatsu, M.
name: Kose, U.
name: Kreslo, I.
name: Laudisio, F.
name: Lauria, A.
name: Ljubicic, A.
name: Longhin, A.
name: Loverre, P.
name: Malgin, A.
name: Malenica, M.
name: Mandrioli, G.
name: Matsuo, T.
name: Matveev, V.
name: Mauri, N.
name: Medinaceli, E.
name: Meregaglia, A.
name: Mikado, S.
name: Miyanishi, M.
name: Mizutani, F.
name: Monacelli, P.
name: Montesi, M. C.
name: Morishima, K.
name: Muciaccia, M. T.
name: Naganawa, N.
name: Naka, T.
name: Nakamura, M.
name: Nakano, T.
name: Niwa, K.
name: Okateva, N.
name: Olchevsky, A.
name: Ogawa, S.
name: Ozaki, K.
name: Paoloni, A.
name: Paparella, L.
name: Park, B. D.
name: Pasqualini, L.
name: Pastore, A.
name: Patrizii, L.
name: Pessard, H.
name: Pistillo, C.
name: Podgrudkov, D.
name: Polukhina, N.
name: Pozzato, M.
name: Pupilli, F.
name: Roda, M.
name: Roganova, T.
name: Rokujo, H.
name: Rosa, G.
name: Ryazhskaya, O.
name: Sadovsky, A.
name: Sato, O.
name: Schembri, A.
name: Shakiryanova, I.
name: Shchedrina, T.
name: Shibuya, H.
name: Shibayama, E.
name: Shiraishi, T.
name: Simone, S.
name: Sirignano, C.
name: Sirri, G.
name: Sotnikov, A.
name: Spinetti, M.
name: Stanco, L.
name: Starkov, N.
name: Stellacci, S. M.
name: Stipcevic, M.
name: Strolin, P.
name: Takahashi, S.
name: Tenti, M.
name: Terranova, F.
name: Tioukov, V.
name: Tufanli, S.
name: Ustyuzhanin, A.
name: Vasina, S.
name: Vilain, P.
name: Voevodina, E.
name: Votano, L.
name: Vuilleumier, J. L.
name: Wilquet, G.
name: Wonsak, B.
name: Yoon, C. S.
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: The OPERA experiment was designed to study $ν_μ\toν_τ$ oscillations in appearance mode in the CNGS neutrino beam. In this letter we report the final analysis of the full data sample collected between 2008 and 2012, corresponding to $17.97\cdot 10^{19}$ protons on target. Selection criteria looser than in previous analyses have produced ten $ν_τ$ candidate events, thus reducing the statistical uncertainty in the measurement of the oscillation parameters and of $ν_τ$ properties. A multivariate approach for event identification has been applied to the candidate events and the discovery of $ν_τ$ appearance is confirmed with an improved significance level of 6.1 $σ$. $Δm^2_{23}$ has been measured, in appearance mode, with an accuracy of 20%. The measurement of $ν_τ$ CC cross-section, for the first time with a negligible contamination from $\barν_τ$, and the first direct observation of the $ν_τ$ lepton number are also reported.
description: 7 pages, 3 figures