[1] The Ohio State University, Department of Physics, Columbus,OH, United States
[2] Physics Department, Columbia University, New York,NY,10027, United States
[3] Department of Physics and Astronomy, DePauw University, Greencastle,IN,46135-0037, United States
[4] Center for Astrophysics, Harvard & Smithsonian, Cambridge,MA,02138, United States
[5] Department of Physics, Washington University, St. Louis,MO,63130, United States
[6] Department of Physics and Astronomy, Barnard College, Columbia University, NY,10027, United States
[7] Physics Department, California Polytechnic State University, San Luis Obispo,CA,94307, United States
[8] Department of Physics and Astronomy, Iowa State University, Ames,IA,50011, United States
[9] Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park,PA,16802, United States
[10] School of Physics, University College Dublin, Dublin 4, Belfield, Ireland
[11] Department of Physics and Astronomy, The Bartol Research Institute, University of Delaware, Newark,DE,19716, United States
[12] School of Physics and Astronomy, University of Minnesota, Minneapolis,MN,55455, United States
[13] Department of Physics, California State University, East Bay, Hayward,CA,94542, United States
[14] School of Physics, Center for Relativistic Astrophysics, Georgia Institute of Technology, 837 State Street NW, Atlanta,GA,30332-0430, United States
[15] School of Physics, National University of Ireland Galway, University Road, Galway, Ireland
[16] DESY, Platanenallee 6, Zeuthen,15738, Germany
[17] Physics Department, McGill University, Montreal,QC,H3A 2T8, Canada
[18] Santa Cruz Institute for Particle Physics, Department of Physics, University of California, Santa Cruz,CA,95064, United States
[19] Department of Physics and Astronomy, University of Utah, 115 S 1400 E #201, Salt Lake City,UT,84112, United States
[20] Department of Physics and Astronomy, University of Alabama, Tuscaloosa,AL,35487, United States
[21] Department of Physics and Astronomy, University of Iowa, Van Allen Hall, Iowa City,IA,52242, United States
[22] Institute of Particle and Cosmos Physics, Universidad Complutense de Madrid, Madrid,28040, Spain
[23] Department of Physics and Astronomy, University of California, Los Angeles,CA,90095, United States
[24] Institute of Physics and Astronomy, University of Potsdam, Potsdam-Golm,14476, Germany
[25] Department of Physical Sciences, Munster Technological University, Bishopstown, Cork,T12 P928, Ireland
[26] Department of Physics and Astronomy, Purdue University, West Lafayette,IN,47907, United States