1. Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027, USA.
2. Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, USA.
3. Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
4. Department of Physics, Washington University, St. Louis, MO 63130, USA.
5. Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645, USA.
6. School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK.
7. Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA.
8. School of Physics, University College Dublin, Belfield, Dublin 4, Ireland.
9. School of Physics, National University of Ireland Galway, University Road, Galway, Ireland.
10. Physics Department, California Polytechnic State University, San Luis Obispo, CA 94307, USA.
11. Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605, USA.
12. Department of Physics, Purdue University, West Lafayette, IN 47907, USA.
13. Department of Physics, Grinnell College, Grinnell, IA 50112–1690, USA.
14. Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802, USA.
15. Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112, USA.
16. School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, USA.
17. Department of Physics and Astronomy, University of Iowa, Van Allen Hall, Iowa City, IA 52242, USA.
18. Physics Department, McGill University, Montreal, Quebec H3A 2T8, Canada.
19. Department of Physics and Astronomy and the Bartol Research Institute, University of Delaware, Newark, DE 19716, USA.
20. Enrico Fermi Institute, University of Chicago, Chicago, IL 60637, USA.
21. Deutsches Elektronen Synchrotron, Platanenallee 6, 15738 Zeuthen, Germany.
22. Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA.
23. Department of Physics and Astronomy, DePauw University, Greencastle, IN 46135–0037, USA.
24. Department of Life and Physical Sciences, Galway-Mayo Institute of Technology, Dublin Road, Galway, Ireland.
25. Institut für Physik und Astronomie, Universität Potsdam, 14476 Potsdam-Golm, Germany.
26. Department of Applied Physics and Instrumentation, Cork Institute of Technology, Bishopstown, Cork, Ireland.
27. Department of Physics, Columbia University, New York, NY 10027.