[1] Univ Lyon 1, Univ Lyon, CNRS IN2P3, IP2I Lyon, F-69622 Villeurbanne, France
[2] Carleton Univ, Dept Phys, Ottawa, ON, Canada
[3] Univ Zaragoza, Ctr Astroparticulas & Fis Altas Energias, Zaragoza, Spain
[4] Georg August Univ, Inst Theoret Phys, Gottingen, Germany
[5] Univ Federico II, Phys Dept, Naples, Italy
[6] INFN Napoli, Naples, Italy
[7] Univ Nottingham, Sch Phys & Astron, Nottingham, England
[8] CERN, Geneva, Switzerland
[9] Johannes Gutenberg Univ Mainz, Mainz, Germany
[10] Max Planck Inst Phys & Astrophys, Munich, Germany
[11] Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA
[12] Univ Oxford, Dept Phys, Oxford, England
[13] Nicolaus Copernicus Astron Ctr PAS, Astrocent, Warsaw, Poland
[14] Natl Ctr Nucl Res, Warsaw, Poland
[15] Univ Freiburg, Inst Phys, Freiburg, Germany