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arXiv · 1507.01417

Discovery of tau neutrino appearance in the CNGS neutrino beam with the OPERA experiment

OPERA Collaboration·N. Agafonova·A. Aleksandrov·A. Anokhina·S. Aoki·A. Ariga·T. Ariga·D. Bender·A. Bertolin·I. Bodnarchuk·C. Bozza·R. Brugnera·A. Buonaura·S. Buontempo·B. Büttner·M. Chernyavsky·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·R. A. Fini·F. Fornari·T. Fukuda·G. Galati·A. Garfagnini·J. Goldberg·Y. Gornushkin·G. Grella·A. M. Guler·C. Gustavino·C. Hagner·T. Hara·H. Hayakawa·A. Hollnagel·B. Hosseini·K. Ishiguro·K. Jakovcic·C. Jollet·C. Kamiscioglu·M. Kamiscioglu·J. H. Kim·S. H. Kim·N. Kitagawa·B. Klicek·K. Kodama·M. Komatsu·U. Kose·I. Kreslo·F. Laudisio·A. Lauria·A. Ljubicic·A. Longhin·P. F. Loverre·A. Malgin·M. Malenica·G. Mandrioli·T. Matsuo·T. Matsushita·V. Matveev·N. Mauri·E. Medinaceli·A. Meregaglia·S. Mikado·M. Miyanishi·F. Mizutani·P. Monacelli·M. C. Montesi·K. Morishima·M. T. Muciaccia·N. Naganawa·T. Naka·M. Nakamura·T. Nakano·Y. Nakatsuka·K. Niwa·S. Ogawa·A. Olchevsky·T. Omura·K. Ozaki·A. Paoloni·L. Paparella·B. D. Park·I. G. Park·L. Pasqualini·A. Pastore·L. Patrizii·H. Pessard·C. Pistillo
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Abstract

The OPERA experiment was designed to search for $\nu_{\mu} \rightarrow \nu_{\tau}$ oscillations in appearance mode, i.e. by detecting the $\tau$-leptons produced in charged current $\nu_{\tau}$ interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of $\nu_{\mu} \rightarrow \nu_{\tau}$ appearance, achieved with four candidate events in a sub-sample of the data, was previously reported. In this paper, a fifth $\nu_{\tau}$ candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow assessing the discovery of $\nu_{\mu}\rightarrow \nu_{\tau}$ oscillations in appearance mode with a significance larger than 5 $\sigma$.

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OPERA Collaboration, N. Agafonova, A. Aleksandrov, A. Anokhina, S. Aoki, A. Ariga, T. Ariga, D. Bender, A. Bertolin, I. Bodnarchuk, C. Bozza, R. Brugnera, A. Buonaura, S. Buontempo, B. Büttner, M. Chernyavsky, 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, R. A. Fini, F. Fornari, T. Fukuda, G. Galati, A. Garfagnini, J. Goldberg, Y. Gornushkin, G. Grella, A. M. Guler, C. Gustavino, C. Hagner, T. Hara, H. Hayakawa, A. Hollnagel, B. Hosseini, K. Ishiguro, K. Jakovcic, C. Jollet, C. Kamiscioglu, M. Kamiscioglu, J. H. Kim, S. H. Kim, N. Kitagawa, B. Klicek, K. Kodama, M. Komatsu, U. Kose, I. Kreslo, F. Laudisio, A. Lauria, A. Ljubicic, A. Longhin, P. F. Loverre, A. Malgin, M. Malenica, G. Mandrioli, T. Matsuo, T. Matsushita, V. Matveev, N. Mauri, E. Medinaceli, A. Meregaglia, S. Mikado, M. Miyanishi, F. Mizutani, P. Monacelli, M. C. Montesi, K. Morishima, M. T. Muciaccia, N. Naganawa, T. Naka, M. Nakamura, T. Nakano, Y. Nakatsuka, K. Niwa, S. Ogawa, A. Olchevsky, T. Omura, K. Ozaki, A. Paoloni, L. Paparella, B. D. Park, I. G. Park, L. Pasqualini, A. Pastore, L. Patrizii, H. Pessard, C. Pistillo. 2015-07-06. Discovery of tau neutrino appearance in the CNGS neutrino beam with the OPERA experiment. https://doi.org/10.1103/physrevlett.115.121802

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