[1] Univ Erlangen Nurnberg, Erlangen Ctr Astroparticle Phys, D-91058 Erlangen, Germany
[2] Univ Valencia, CSIC, IFIC, Valencia 46071, Spain
[3] CNRS, IN2P3, CPPM, F-13288 Marseille 9, France
[4] Univ Mediterranee, F-13288 Marseille 9, France
[5] Inst Univ Technol Colmar, GRPHE, F-68008 Colmar, France
[6] Ist Nazl Fis Nucl, Sez Genova, I-16146 Genoa, Italy
[7] CEA Saclay, Direct Sci Mat, Inst Rech Lois Fondamentales Univers, Serv Elect Detecteurs & Informat, F-91191 Gif Sur Yvette, France
[8] Univ Politecn Valencia, Inst Invest Gestio Integrada Zones Costaneres IGI, Gandia 46730, Spain
[9] FOM Inst Subatomaire Fys Nikhef, NL-1098 XG Amsterdam, Netherlands
[10] Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy
[11] Univ Paris 07, CEA, Observ Paris, CNRS,APC Lab AstroParticule & Cosmol,UMR 7164, F-75205 Paris 13, France
[12] LAM, F-13388 Marseille 13, France
[13] Univ Bologna, Dipartimento Fis, I-40127 Bologna, Italy
[14] Ist Nazl Fis Nucl, Sez Bologna, I-40127 Bologna, Italy
[15] Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy
[16] Ist Nazl Fis Nucl, Sez Roma, I-00185 Rome, Italy
[17] Univ Blaise Pascal, Clermont Univ, CNRS, Phys Corpusculaire Lab,IN2P3, F-63000 Clermont Ferrand, France
[18] Univ Pisa, Dipartimento Fis, I-56127 Pisa, Italy
[19] Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy
[20] INAF IASF, I-40129 Bologna, Italy
[21] Geoazur Univ Nice Sophia Antipolis, CNRS, INSU, Observ Cote Azur,IRD, F-06235 Villefranche Sur Mer, France
[22] Univ Paris 06, F-06235 Villefranche Sur Mer, France
[23] Ist Nazl Fis Nucl, LNS, I-95123 Catania, Italy
[24] CEA Saclay, Direct Sci Mat, Inst Rech Lois Fondamentales Univers, Serv Phys Particules, F-91191 Gif Sur Yvette, France
[25] CNRS, Ctr Oceanol Marseille, INSU, F-13288 Marseille 9, France
[26] Univ Paris 11, Dept Phys, F-91403 Orsay, France
[27] Univ Strasbourg, IPHC, F-67037 Strasbourg 2, France
[28] CNRS, IN2P3, F-67037 Strasbourg 2, France
[29] Royal Netherlands Inst Sea Res NIOZ, NL-1797 SZ T Horntje, Texel, Netherlands
[30] Univ Groningen, Kernfys Versneller Inst, NL-9747 AA Groningen, Netherlands
[31] Univ Utrecht, Fac Betawetenschappen, NL-3584 CC Utrecht, Netherlands
[32] Univ Amsterdam, Inst Hoge Energie Fys, NL-1098 XG Amsterdam, Netherlands
[33] Univ Catania, Dipartimento Fis & Astron, I-95125 Catania, Italy
[34] Univ Wisconsin, Madison, WI 53715 USA
[35] Inst Space Sci, R-77125 Bucharest, Magurele, Romania
[36] Univ Genoa, Dipartimento Fis, I-16146 Genoa, Italy
[37] Inst Theoret & Expt Phys, Moscow 117218, Russia
[38] Leiden Univ, NL-2300 RA Leiden, Netherlands