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arXiv · 1401.2079

Evidence for $\nu_\mu \to \nu_\tau$ appearance in the CNGS neutrino beam with the OPERA experiment

N. Agafonova·A. Aleksandrov·A. Anokhina·S. Aoki·A. Ariga·T. Ariga·T. Asada·D. Autiero·A. Ben Dhahbi·A. Badertscher·D. Bender·A. Bertolin·C. Bozza·R. Brugnera·F. Brunet·G. Brunetti·A. Buonaura·S. Buontempo·B. Buettner·L. Chaussard·M. Chernyavsky·V. Chiarella·A. Chukanov·L. Consiglio·N. D'Ambrosio·G. De Lellis·M. De Serio·P. Del Amo Sanchez·A. Di Crescenzo·D. Di Ferdinando·N. Di Marco·S. Dmitrievski·M. Dracos·D. Duchesneau·S. Dusini·T. Dzhatdoev·J. Ebert·A. Ereditato·J. Favier·T. Ferber·G. Ferone·R. A. Fini·T. Fukuda·G. Galati·A. Garfagnini·G. Giacomelli·C. Goellnitz·J. Goldberg·Y. Gornushkin·G. Grella·F. Grianti·M. Guler·C. Gustavino·C. Hagner·K. Hakamata·T. Hara·T. Hayakawa·M. Hierholzer·A. Hollnagel·B. Hosseini·H. Ishida·K. Ishiguro·M. Ishikawa·K. Jakovcic·C. Jollet·C. Kamiscioglu·M. Kamiscioglu·T. Katsuragawa·J. Kawada·H. Kawahara·J. H. Kim·S. H. Kim·M. Kimura·N. Kitagawa·B. Klicek·K. Kodama·M. Komatsu·U. Kose·I. Kreslo·A. Lauria·J. Lenkeit·A. Ljubicic·A. Longhin·P. Loverre·A. Malgin·G. Mandrioli·J. Marteau·T. Matsuo·V. Matveev·N. Mauri·E. Medinaceli·A. Meregaglia·P. Migliozzi·S. Mikado·M. Miyanishi·E. Miyashita·P. Monacelli·M. C. Montesi·K. Morishima·M. T. Muciaccia
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Abstract

The OPERA experiment is designed to search for $\nu_{\mu} \rightarrow \nu_{\tau}$ oscillations in appearance mode i.e. through the direct observation of the $\tau$ lepton in $\nu_{\tau}$ charged current interactions. The experiment has taken data for five years, since 2008, with the CERN Neutrino to Gran Sasso beam. Previously, two $\nu_{\tau}$ candidates with a $\tau$ decaying into hadrons were observed in a sub-sample of data of the 2008-2011 runs. Here we report the observation of a third $\nu_\tau$ candidate in the $\tau^-\to\mu^-$ decay channel coming from the analysis of a sub-sample of the 2012 run. Taking into account the estimated background, the absence of $\nu_{\mu} \rightarrow \nu_{\tau}$ oscillations is excluded at the 3.4 $\sigma$ level.

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N. Agafonova, A. Aleksandrov, A. Anokhina, S. Aoki, A. Ariga, T. Ariga, T. Asada, D. Autiero, A. Ben Dhahbi, A. Badertscher, D. Bender, A. Bertolin, C. Bozza, R. Brugnera, F. Brunet, G. Brunetti, A. Buonaura, S. Buontempo, B. Buettner, L. Chaussard, M. Chernyavsky, V. Chiarella, A. Chukanov, L. Consiglio, N. D'Ambrosio, G. De Lellis, M. De Serio, P. Del Amo Sanchez, A. Di Crescenzo, D. Di Ferdinando, N. Di Marco, S. Dmitrievski, M. Dracos, D. Duchesneau, S. Dusini, T. Dzhatdoev, J. Ebert, A. Ereditato, J. Favier, T. Ferber, G. Ferone, R. A. Fini, T. Fukuda, G. Galati, A. Garfagnini, G. Giacomelli, C. Goellnitz, J. Goldberg, Y. Gornushkin, G. Grella, F. Grianti, M. Guler, C. Gustavino, C. Hagner, K. Hakamata, T. Hara, T. Hayakawa, M. Hierholzer, A. Hollnagel, B. Hosseini, H. Ishida, K. Ishiguro, M. Ishikawa, K. Jakovcic, C. Jollet, C. Kamiscioglu, M. Kamiscioglu, T. Katsuragawa, J. Kawada, H. Kawahara, J. H. Kim, S. H. Kim, M. Kimura, N. Kitagawa, B. Klicek, K. Kodama, M. Komatsu, U. Kose, I. Kreslo, A. Lauria, J. Lenkeit, A. Ljubicic, A. Longhin, P. Loverre, A. Malgin, G. Mandrioli, J. Marteau, T. Matsuo, V. Matveev, N. Mauri, E. Medinaceli, A. Meregaglia, P. Migliozzi, S. Mikado, M. Miyanishi, E. Miyashita, P. Monacelli, M. C. Montesi, K. Morishima, M. T. Muciaccia. 2014-01-09. Evidence for $\nu_\mu \to \nu_\tau$ appearance in the CNGS neutrino beam with the OPERA experiment. https://doi.org/10.1103/physrevd.89.051102

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