1. Department of Physics, Center for Neutrino Physics, Virginia Tech, Blacksburg, VA 24061, USA
2. Division of Liberal Arts, Numazu National College of Technology, Numazu, Shizuoka 410-8501, Japan
3. Department of Applied Physics, Fukuoka University, Fukuoka 814-0180, Japan
4. Institute for Theoretical Physics, University of Wroclaw, pl. M. Borna 9, PL-50-204 Wroclaw, Poland
5. Max Planck Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching, Germany
6. National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588, Japan