Letter of Intent: The Hyper-Kamiokande Experiment --- Detector Design   and Physics Potential ---
  We propose the Hyper-Kamiokande (Hyper-K) detector as a next generation underground water Cherenkov detector. It will serve as a far detector of a long baseline neutrino oscillation experiment envisioned for the upgraded J-PARC, 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 astronomical origins. The baseline design of Hyper-K is based on the highly successful Super-K, taking full advantage of a well-proven technology. (to be continued) 
K. Abe, T. Abe, H. Aihara, Y. Fukuda, Y. Hayato, K. Huang, A. K.   Ichikawa, M. Ikeda, K. Inoue, H. Ishino, Y. Itow, T. Kaji...
hep-ex astro-ph.IM