Hyper - Kamiokande Physics Opportunities

We propose the Hyper-Kamiokande (Hyper-K) detector as a next generation underground water Cherenkov detector [1]. It will serve as a far detector of a long baseline neutrino oscillation experiment envisioned for the upgraded J-PARC beam, and as a detector capable of observing, far beyond the sensitivity of the Super-Kamiokande (Super-K) detector, proton decays, atmospheric neutrinos, and neutrinos from astrophysical origins. The current baseline design of Hyper-K is based on the highly successful Super-K detector, taking full advantage of a well-proven technology. Hyper-K consists of two cylindrical tanks lying side-by-side, the outer dimensions of each tank being 48(W )× 54(H)× 250(L) m3. The total (fiducial) mass of the detector is 0.99 (0.56) million metric tons, which is about 20 (25) times larger than that of Super-K. A proposed location for Hyper-K is about 8 km south of Super-K (and 295 km away from J-PARC) at an underground depth of 1,750 meters water equivalent (m.w.e.). The inner detector region of the Hyper-K detector is viewed by 99,000 20-inch PMTs, corresponding to the PMT density of 20% photo-cathode coverage (one half of that of Super-K). The Hyper-K project is envisioned to be completely open to the international community. The current working group contains members from Canada, Japan, Korea, Spain, Switzerland, Russia, the United Kingdom and the United States. The United States physics community has a long history of making contributions to the neutrino physics program in Japan. In Kamiokande, Super-Kamiokande, K2K and T2K, US physicists have played important roles building and operating beams, near detectors, and large underground water Cherenkov detectors. This set of three onepage whitepapers prepared for the US Snowmass process describes the opportunities for future physics discoveries at the Hyper-K facility with beam, atmospheric and astrophysical neutrinos. ∗Project contact: Tsuyoshi Nakaya ar X iv :1 30 9. 01 84 v1 [ he pex ] 1 S ep 2 01 3 The Hyper-Kamiokande Working Group Boston University (USA): E. Kearns, J.L. Stone Chonnam National University (Korea): K.K. Joo Duke University (USA): T. Akiri, A. Himmel, K. Scholberg, C.W. Walter Earthquake Research Institute, The University of Tokyo (Japan): A. Taketa, H.K.M. Tanaka ETH Zurich (Switzerland): A. Rubbia Institute for Nuclear Research (Russia): A. Izmaylov, M. Khabibullin, Y. Kudenko Imperial College London (UK): M. Malek, Y. Uchida, M.O. Wascko Iowa State University (USA): I. Anghel, G. Davies, M.C. Sanchez, T. Xin Kamioka Observatory, ICRR, The University of Tokyo (Japan): K. Abe, Y. Haga, Y. Hayato, J. Kameda, Y. Kishimoto, M. Miura, S. Moriyama, M. Nakahata, S. Nakayama, H. Sekiya, M. Shiozawa, Y. Suzuki, A. Takeda, H. Tanaka, T. Tomura, R. Wendell Kavli IPMU, The University of Tokyo (Japan): M. Hartz, L. Marti, K.Nakamura, M.R. Vagins KEK (Japan): M. Friend, T. Ishida, T. Kobayashi, Y. Oyama Kobe University (Japan): A. T. Suzuki, Y. Takeuchi Kyoto University (Japan): S. Hirota, K. Huang, A. K. Ichikawa, M. Ikeda, A. Minamino, T. Nakaya, K. Tateishi Lancaster University (UK): A. Finch, L.L. Kormos, J. Nowak, H.M. O’Keeffe, P.N. Ratoff Los Alamos National Laboratory (USA): G. Sinnis Louisiana State University (USA): F.d.M. Blaszczyk, J. Insler, T. Kutter, O. Perevozchikov, M. Tzanov Miyagi University of Education (Japan): Y.Fukuda Nagoya University (Japan): K.Choi, T. Iijima, Y. Itow Okayama University (Japan): H. Ishino, Y. Koshio, T. Mori, M. Sakuda, T. Yano Osaka City University (Japan): Y. Seiya, K. Yamamoto Pontif́ıcia Universidade Católica do Rio de Janeiro (Brazil): H. Minakata, H. Nunokawa Queen Mary, University of London (UK): F. Di Lodovico, T. Katori, R. Sacco, B. Still, R. Terri, J.R. Wilson Seoul National University (Korea): S. B. Kim State University of New York at Stony Brook (USA): J. Adam, J. Imber, C. K. Jung, C. McGrew, J.L. Palomino, C. Yanagisawa STFC Rutherford Appleton Laboratory (UK): D. Wark, A. Weber Sungkyunkwan University (Korea): C. Rott The California State University Dominguez Hills (USA): K. Ganezer, B. Hartfiel, J. Hill The University of Tokyo (Japan): H. Aihara, Y. Suda, M. Yokoyama Tohoku University (Japan): K. Inoue, M. Koga, I. Shimizu Research Center for Cosmic Neutrinos, ICRR, The University of Tokyo (Japan): T. Irvine, T. Kajita, I. Kametani, Y. Nishimura, K. Okumura, E. Richard Tokyo Institute of Technology (Japan): M. Ishitsuka, M. Kuze, Y. Okajima TRIUMF (Canada): P. Gumplinger, A. Konaka, T. Lindner, K. Mahn, J.-M. Poutissou, F. Retiere, M. Scott, M.J. Wilking University Autonoma Madrid (Spain): L. Labarga University of British Columbia (Canada): S.M. Oser, H.A. Tanaka University of Geneva (Switzerland):A. Blondel, A. Bravar, F. Dufour, Y. Karadhzov, A. Korzenev, E. Noah, M. Ravonel, M. Rayner, R. Asfandiyarov, A. Haesler, C. Martin, E. Scantamburlo University of Hawaii (USA): J.G. Learned University of Regina (Canada): M. Barbi University of Toronto (Canada): J.F. Martin University of California, Davis (USA): M. Askins, M.Bergevin, R. Svoboda University of California, Irvine (USA): G. Carminati, S. Horiuchi, W.R. Kropp, S. Mine, M.B. Smy, H.W. Sobel University of Liverpool (UK): N. McCauley, C. Touramanis University of Oxford (UK): G. Barr, D. Wark, A. Weber University of Pittsburgh (USA): V. Paolone University of Sheffield (UK): J.D. Perkin, L.F. Thompson University of Washington (USA): J. Detwiler, N. Tolich, R. J. Wilkes University of Warwick (UK): G.J. Barker, S. Boyd, D.R. Hadley, M.D. Haigh University of Winnipeg (Canada): B. Jamieson Virginia Tech (USA): S. M. Manecki, C. Mariani, S. D. Rountree, R. B. Vogelaar York University (Canada): S. Bhadra Exploring CP violation with the upgraded J-PARC Beam