[1] IN2P3, CNRS, Phys Particules Lab, F-74019 Annecy Le Vieux, France
[2] Univ Autonoma Barcelona, Inst Fis Altes Energies, E-08193 Barcelona, Spain
[3] Ist Nazl Fis Nucl, Sezione Bari, Dipartimento Fis, I-70126 Bari, Italy
[4] Acad Sinica, Inst High Energy Phys, Beijing, Peoples R China
[5] CERN, European Lab Particle Phys, CH-1211 Geneva 23, Switzerland
[6] Univ Blaise Pascal, Phys Corpusculaire Lab, IN2P3, CNRS, F-63177 Clermont Ferrand, France
[7] Niels Bohr Inst, DK-2100 Copenhagen, Denmark
[8] Democritos Nucl Res Ctr, GR-15310 Attiki, Greece
[9] Ecole Polytech, Lab Phys Nucl & Hautes Energies, IN2P3, CNRS, F-91128 Palaiseau, France
[10] Univ Florence, Dipartimento Fis, Ist Nazl Fis Nucl, Sezione Firenze, I-50125 Florence, Italy
[11] Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy
[12] Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland
[13] Heidelberg Univ, Kirchoff Inst Phys, D-69120 Heidelberg, Germany
[14] Univ London Imperial Coll Sci Technol & Med, Dept Phys, London SW7 2BZ, England
[15] Univ Innsbruck, Inst Expt Phys, A-6020 Innsbruck, Austria
[16] Univ Lancaster, Dept Phys, Lancaster LA1 4YB, England
[17] Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany
[18] Univ Mediterranee, Ctr Phys Particules Marseille, IN2P3, CNRS, F-13288 Marseille, France
[19] Univ Milan, Dipartimento Fis, I-20133 Milan, Italy
[20] Ist Nazl Fis Nucl, Sezione Milano, I-20133 Milan, Italy
[21] Max Planck Inst Phys & Astrophys, Werner Heisenberg Inst Phys, D-80805 Munich, Germany
[22] Univ Paris 11, Accelerateur Lineaire Lab, IN2P3, CNRS, F-91898 Orsay, France
[23] Univ Pisa, Dipartimento Fis, Ist Nazl Fis Nucl, Sezione Pisa, I-56010 Pisa, Italy
[24] Scuola Normale Super Pisa, I-56010 Pisa, Italy
[25] Univ London Royal Holloway & Bedford New Coll, Dept Phys, Egham TW20 0EX, Surrey, England
[26] Rutherford Appleton Lab, Particule Phys Dept, Didcot OX11 0QX, Oxon, England
[27] Ctr Etud Saclay, Serv Phys Particules, DAPNIA, CEA, F-91191 Gif Sur Yvette, France
[28] Univ Calif Santa Cruz, Inst Particle Phys, Santa Cruz, CA 95064 USA
[29] Univ Sheffield, Dept Phys, Sheffield S3 7RH, S Yorkshire, England
[30] Univ Siegen, Fachbereich Phys, D-57068 Siegen, Germany
[31] Univ Trieste, Dipartmento Fis, I-34127 Trieste, Italy
[32] Ist Nazl Fis Nucl, Sezione Trieste, I-34127 Trieste, Italy
[33] Univ Washington, Seattle, WA 98195 USA
[34] Univ Wisconsin, Dept Phys, Madison, WI 53706 USA
[35] Univ Barcelona, Barcelona 08208, Spain
[36] CERN, CH-1211 Geneva 23, Switzerland
[37] Univ Palermo, Dipartimento Fis & Tecnol Relat, Palermo, Italy
[38] Dipartimento Fis, I-95129 Catania, Italy
[39] Ist Nazl Fis Nucl, Sezione Catania, I-95129 Catania, Italy
[40] CNR, Ist Cosmogeofis, I-10133 Turin, Italy
[41] Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England