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

The OPERA experiment is searching for nu_mu -> nu_tau oscillations in appearance mode i.e. via the direct detection of tau leptons in nu_tau charged current interactions. The evidence of nu_mu -> nu_tau appearance has been previously reported with three nu_tau candidate events using a sub-sample of data from the 2008-2012 runs. We report here a fourth nu_tau candidate event, with the tau decaying into a hadron, found after adding the 2012 run events without any muon in the final state to the data sample. Given the number of analysed events and the low background, nu_mu -> nu_tau oscillations are established with a significance of 4.2sigma.

V. Tioukov | S. Tufanli | S. Buontempo | A. Di Crescenzo | S. Dusini | E. Medinaceli | L. Patrizii | G. Sirri | L. Stanco | Y. Gornushkin | S. H. Kim | I. Kreslo | D. Duchesneau | H. Pessard | A. Sheshukov | A. Zghiche | S. Ogawa | H. Shibuya | A. Ljubicic | C. Jollet | A. Meregaglia | A. Garfagnini | A. Lauria | M. Spinetti | A. Paoloni | R. Brugnera | C. Bozza | G. Grella | M. Dracos | F. Terranova | G. Mandrioli | M. Malenica | G. De Lellis | T. Nakano | J. Ebert | I. G. Park | S. Takahashi | C. Kamiscioglu | N. Okateva | T. Shchedrina | L. Pasqualini | K. Ishiguro | A. Buonaura | L. Consiglio | A. Ereditato | M. Sioli | M. Meyer | C. Sirignano | L. Votano | M. Roda | S. Kim | A. Lauria | A. Ereditato | T. Hayakawa | S. Ogawa | H. Shibuya | M. Dracos | S. Buontempo | J. Kim | M. C. Montesi | C. Yoon | M. Stipčević | A. Olshevsky | Y. Gornushkin | D. Duchesneau | P. Loverre | L. Consiglio | A. Sheshukov | T. Nakano | P. Sanchez | A. Zghiche | M. Meyer | R. Brugnera | A. Garfagnini | N. Starkov | G. Wilquet | M. Yoshimoto | A. Ariga | C. Pistillo | A. Crescenzo | G. Galati | A. Bertolin | A. Buonaura | M. Serio | R. Fini | M. Sioli | V. Matveev | J. Goldberg | A. Paoloni | S. Dusini | A. Longhin | L. Stanco | C. Hagner | C. Jollet | A. Meregaglia | A. Pastore | N. Polukhina | S. Simone | P. Vilain | S. Aoki | T. Ariga | I. Kreslo | S. Takahashi | G. Lellis | N. Agafonova | A. Aleksandrov | A. Anokhina | D. Bender | C. Bozza | B. Büttner | M. Chernyavsky | A. Chukanov | S. Dmitrievski | T. Dzhatdoev | J. Ebert | T. Fukuda | G. Grella | C. Gustavino | T. Hara | A. Hollnagel | B. Hosseini | K. Ishiguro | K. Jakovčić | Ç. Kamışcıoğlu | M. Kamiscioglu | N. Kitagawa | B. Kliček | K. Kodama | M. Komatsu | U. Kose | A. Ljubičić | A. Malgin | M. Malenica | G. Mandrioli | T. Matsuo | N. Mauri | E. Medinaceli | S. Mikado | M. Miyanishi | P. Monacelli | K. Morishima | M. Muciaccia | N. Naganawa | T. Naka | M. Nakamura | Y. Nakatsuka | K. Niwa | T. Omura | K. Ozaki | B. D. Park | L. Pasqualini | L. Patrizii | H. Pessard | D. Podgrudkov | M. Pozzato | F. Pupilli | M. Roda | T. Roganova | H. Rokujo | G. Rosa | O. Ryazhskaya | O. Sato | A. Schembri | T. Shchedrina | T. Shiraishi | G. Shoziyoev | C. Sirignano | G. Sirri | M. Spinetti | S. Stellacci | P. Strolin | M. Tenti | F. Terranova | V. Tioukov | S. Tufanli | L. Votano | J. Vuilleumier | B. Wonsak | S. Zemskova | G. Giacomelli | N. Okateva | I. Shakiryanova | N. Marco | N. Mauri | M. Tenti | C. Hagner | A. Olshevsky | D. Di Ferdinando | G. Giacomelli | C. Gustavino | P. Monacelli | T. Asada | N. Di Marco | T. Katsuragawa | F. Pupilli | A. Umemoto | D. Ferdinando | C. S. Yoon | M. De Serio | M. T. Muciaccia | N. D'Ambrosio | C. Pistillo | T. Hayakawa | A. Bertolin | A. Longhin | J. L. Vuilleumier | P. Vilain | G. Wilquet | P. Strolin | A. Ariga | K. Kodama | S. Aoki | T. Hara | J. Kawada | A. Umemoto | N. Polukhina | G. Rosa | G. Galati | V. Matveev | A. Pastore | A. Schembri | S. Simone | I. Yaguchi | R. A. Fini | J. Goldberg | M. Miyanishi | M. Nakamura | H. Ishida | J. Lenkeit | M. Vladimirov | N. Naganawa | M. Pozzato | C. Goellnitz | J. Kawada | A. Aleksandrov | A. Anokhina | D. Bender | A. Chukanov | S. Dmitrievski | T. Dzhatdoev | M. Kamiscioglu | P. Loverre | T. Naka | D. Podgrudkov | T. Roganova | O. Sato | N. Starkov | M. Yoshimoto | S. Zemskova | T. Ariga | T. Fukuda | C. Goellnitz | B. Klicek | J. Lenkeit | K. Niwa | O. Ryazhskaya | B. Wonsak | M. Chernyavsky | A. Hollnagel | H. Ishida | K. Jakovcic | J. H. Kim | N. Kitagawa | M. Komatsu | U. Kose | A. Malgin | T. Matsuo | S. Mikado | K. Morishima | Y. Nakatsuka | K. Ozaki | H. Rokujo | I. Shakiryanova | G. Shoziyoev | S. M. Stellacci | M. Stipcevic | M. Vladimirov | B. Hosseini | M. Guler | T. Asada | T. Katsuragawa | OPERA Collaboration N. Agafonova | B. Buttne | P. Del Amo Sanchez | M. Guler | H. Kawahara | T. Omura | T. Shiraishi | I. Yaguchi | H. Kawahara | S. Takahashi | N. D’Ambrosio | O. C. N. Agafonova | B. Buttne | S.H. Kim | B. Park | A. Zghiche | M. Meyer | A. Zghiche | T. Fukuda | S. Aoki | Masahiro Yoshimoto

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