[1] Univ Hamburg, Inst Expt Phys, D-22761 Hamburg, Germany
[2] Max Planck Inst Kernphys, D-69029 Heidelberg, Germany
[3] Dublin Inst Adv Studies, Dublin 2, Ireland
[4] Natl Acad Sci Republ Armenia, Yerevan 0019, Armenia
[5] Yerevan Phys Inst, Yerevan 375036, Armenia
[6] Humboldt Univ, Inst Phys, D-12489 Berlin, Germany
[7] Univ Namibia, Dept Phys, Windhoek, Namibia
[8] Univ Durham, Dept Phys, Durham DH1 3LE, England
[9] Univ Amsterdam, Astron Inst Anton Pannekoek, GRAPPA, NL-1098 XH Amsterdam, Netherlands
[10] Uniwersytet Jagiellonski, Astron Observ, PL-30244 Krakow, Poland
[11] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA
[12] Linnaeus Univ, Dept Phys & Elect Engn, S-35195 Vaxjo, Sweden
[13] Ruhr Univ Bochum, Inst Theoret Phys Lehrstuhl Weltraum & Astrophs 4, D-44780 Bochum, Germany
[14] Univ Amsterdam, Inst High Energy Phys, NL-1098 XH Amsterdam, Netherlands
[15] Leopold Franzens Univ, Inst Astro & Teilchenphys, A-6020 Innsbruck, Austria
[16] Ecole Polytech, CNRS, IN2P3, Lab Leprince Ringuet, F-91128 Palaiseau, France
[17] Univ Calif Santa Cruz, Dept Phys, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA
[18] North West Univ, Ctr Space Res, ZA-2520 Potchefstroom, South Africa
[19] Univ Paris Diderot, CNRS, LUTH, Observ Paris, F-92190 Meudon, France
[20] Univ Paris 07, Univ Paris 06, CNRS IN2P3, LPNHE, F-75252 Paris 5, France
[21] Univ Tubingen, Inst Astron & Astrophys, D-72076 Tubingen, Germany
[22] Univ Montpellier 2, CNRS, IN2P3, Lab Univ & Particules Montpellier, F-34095 Montpellier 5, France
[23] CEA Saclay, DSM Irfu, F-91191 Gif Sur Yvette, France
[24] Univ Warsaw, Astron Observ, PL-00478 Warsaw, Poland
[25] PAN, Inst Fizyki Jadrowej, PL-31342 Krakow, Poland
[26] Univ Witwatersrand, Sch Phys, ZA-2050 Johannesburg, South Africa
[27] Heidelberg Univ, D-69117 Heidelberg, Germany
[28] Stockholm Univ, Oskar Klein Ctr, Albanova Univ Ctr, Dept Phys, Stockholm, Sweden
[29] Univ Bordeaux 1, CNRS, IN2P3, CEN Bordeaux Gradignan, F-33175 Gradignan, France
[30] Univ Adelaide, Sch Chem & Phys, Adelaide, SA 5005, Australia
[31] Univ Paris Diderot, CNRS IN2P3, CEA Irfu, APC,Observ Paris,Sorbonne Paris Cite, F-75205 Paris 13, France
[32] UJF Grenoble 1, CNRS INSU, IPAG, UMR 5274, F-38041 Grenoble, France
[33] Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England
[34] Nicolaus Copernicus Astron Ctr, PL-00716 Warsaw, Poland
[35] Univ Potsdam, Inst Phys & Astron, D-14476 Golm, Germany
[36] Univ Savoie, CNRS, IN2P3, Lab Annecy Le Vieux Phys Particules, F-74941 Annecy Le Vieux, France
[37] DESY, D-15738 Zeuthen, Germany
[38] Univ Savoie, CNRS, Lab Annecy Le Vieux Phys Particules, F-74941 Annecy Le Vieux, France
[39] Univ Erlangen Nurnberg, Inst Phys, D-91058 Erlangen, Germany
[40] Nicholas Copernicus Univ, Ctr Astron, PL-87100 Torun, Poland
[41] Univ Free State, Dept Phys, ZA-9300 Bloemfontein, South Africa
[42] Charles Univ Prague, Fac Math & Phys, Inst Particle & Nucl Phys, CR-18000 Prague 8, Czech Republic