¹ Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824
² Department of Physics and Astronomy, University of California, Irvine, CA 92697
³ Department of Physics, University of Maryland, College Park, MD 20742
⁴ Group P-23, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545
⁵ Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030
⁶ Instituto de Astronomía, Universidad Nacional Autónoma de México, D.F., Mexico, 04510
⁷ Current address: High Energy Physics Division, Argonne National Laboratory, Argonne, IL 60439
⁸ Current address: Enrico Fermi Institute, University of Chicago, Chicago, IL 60637
⁹ Department of Physics, New York University, New York, NY 10003
¹⁰ NASA Goddard Space Flight Center, Greenbelt, MD 20771
¹¹ Department of Physics, University of New Hampshire, Durham, NH 03824
¹² Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration
¹³ Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA 95064
¹⁴ Ohio State University, Lima, OH 45804