[1] Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA
[2] Japanese Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Chofu, Tokyo, Japan
[3] Kanagawa Univ, Fac Engn, Kanagawa, Japan
[4] Univ Tokyo, Inst Cosm Ray Res, Tokyo, Japan
[5] Tokyo Inst Technol, Dept Phys, Tokyo, Japan
[6] Aoyama Gakuin Univ, Dept Phys, Tokyo, Japan
[7] Yokohama Natl Univ, Dept Phys, Yokohama, Kanagawa, Japan
[8] Hirosaki Univ, Dept Earth & Environm Sci, Hirosaki, Aomori, Japan
[9] Natl Inst Radiol Sci, Chiba, Japan
[10] Shibaura Inst Technol, Dept Elect Informat Syst, Tokyo, Japan
[11] Rikkyou Univ, Dept Phys, Toshima, Japan
[12] Kanagawa Univ Human Serv, Kanagawa, Japan
[13] Saitama Univ, Dept Phys, Saitama, Japan
[14] Shinshu Univ, Dept Phys, Matsumoto, Nagano, Japan
[15] NASA, Goddard Space Flight Ctr, Washington, DC USA
[16] Univ Denver, Denver Res Inst, Denver, CO USA
[17] Waseda Univ, Res Inst Sci & Engn, Tokyo, Japan
[18] Washington Univ St Louis, Washington, DC USA
[19] Univ Siena, INFN, Siena, Italy
[20] Univ Florence, INFN, Florence, Italy
[21] Chinese Acad Sci, Purple Mt Observ, Beijing, Peoples R China
[22] Chinese Acad Sci, Inst High Energy Phys, Beijing, Peoples R China