[1] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA
[2] Yale Univ, Dept Phys, New Haven, CT 06520 USA
[3] Univ Calif Davis, Dept Phys, Davis, CA 95616 USA
[4] Cardiff Univ, Dept Phys & Astron, Cardiff CF24 3YB, S Glam, Wales
[5] Univ Chicago, Kavli Inst Cosmol Phys, Chicago, IL 60637 USA
[6] Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA
[7] Univ Chicago, Dept Phys, Chicago, IL 60637 USA
[8] Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA
[9] NIST Quantum Devices Grp, Boulder, CO 80305 USA
[10] McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada
[11] Univ Colorado, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA
[12] Univ Colorado, Dept Phys, Boulder, CO 80309 USA
[13] NASA, Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA
[14] Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA
[15] CALTECH, Pasadena, CA 91125 USA
[16] Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA
[17] Univ Munich, Dept Phys, D-81679 Munich, Germany
[18] Excellence Cluster Universe, D-85748 Garching, Germany
[19] Max Planck Inst Extraterr Phys, D-85748 Garching, Germany
[20] Case Western Reserve Univ, Dept Phys, Ctr Educ & Res Cosmol & Astrophys, Cleveland, OH 44106 USA
[21] Sch Art Inst Chicago, Liberal Arts Dept, Chicago, IL 60603 USA
[22] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA
[23] Univ Calif Berkeley, Dept Phys, Berkeley Ctr Cosmol Phys, Berkeley, CA 94720 USA
[24] Lawrence Berkeley Natl Labs, Berkeley, CA 94720 USA