[1] Univ Autonoma Barcelona, Inst Fis Altes Energies, E-08193 Bellaterra, Barcelona, Spain
[2] Boston Univ, Dept Phys, Boston, MA 02215 USA
[3] Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada
[4] Ctr Saclay, Commissariat Energie Atom & Energies Alternat, IRFU SPP, F-91191 Gif Sur Yvette, France
[5] Chonnam Natl Univ, Dept Phys, Kwangju 500757, South Korea
[6] Dongshin Univ, Dept Phys, Naju 520714, South Korea
[7] Duke Univ, Dept Phys, Durham, NC 27708 USA
[8] Univ Geneva, Sect Phys, DPNC, CH-1211 Geneva 4, Switzerland
[9] Univ Hawaii, Dept Phys & Astron, Honolulu, HI 96822 USA
[10] High Energy Accelerator Res Org KEK, Tsukuba, Ibaraki 3050801, Japan
[11] Hiroshima Univ, Grad Sch Adv Sci Matter, Hiroshima 7398530, Japan
[12] Russian Acad Sci, Inst Nucl Res, Moscow 117312, Russia
[13] Kobe Univ, Kobe, Hyogo 6578501, Japan
[14] Korea Univ, Dept Phys, Seoul 136701, South Korea
[15] Kyoto Univ, Dept Phys, Kyoto 6068502, Japan
[16] Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA
[17] MIT, Dept Phys, Cambridge, MA 02139 USA
[18] Miyagi Univ Educ, Dept Phys, Sendai, Miyagi 9800845, Japan
[19] Niigata Univ, Dept Phys, Niigata 9502181, Japan
[20] Okayama Univ, Dept Phys, Okayama 7008530, Japan
[21] Osaka Univ, Dept Phys, Osaka 5600043, Japan
[22] Univ Roma La Sapienza, I-00185 Rome, Italy
[23] INFN, I-00185 Rome, Italy
[24] Seoul Natl Univ, Dept Phys, Seoul 151747, South Korea
[25] A Soltan Inst Nucl Studies, PL-00681 Warsaw, Poland
[26] SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA
[27] Tokyo Univ Sci, Dept Phys, Chiba 2780022, Japan
[28] Univ Tokyo, Inst Cosm Ray Res, Kamioka Observ, Gifu 5061205, Japan
[29] Univ Tokyo, Inst Cosm Ray Res, Res Ctr Cosm Neutrinos, Chiba 2778582, Japan
[30] TRIUMF, Vancouver, BC V6T 2A3, Canada
[31] Inst Fis Corpuscular, E-46071 Valencia, Spain
[32] Univ Washington, Dept Phys, Seattle, WA 98195 USA
[33] Univ Warsaw, Inst Expt Phys, PL-00681 Warsaw, Poland