[1] McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada
[2] Columbia Univ, Dept Phys, New York, NY 10027 USA
[3] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA
[4] Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada
[5] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA
[6] Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA
[7] Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3059562, Japan
[8] Japan Atom Energy Agcy, Quantum Beam Sci Directorate, Tokai, Ibaraki 3191195, Japan
[9] Canadian Inst Adv Res, Toronto, ON M5G 1Z8, Canada