[1] Univ Washington, Ctr Expt Nucl Phys, Seattle, WA 98195 USA
[2] Univ Washington, Dept Phys, Seattle, WA 98195 USA
[3] Univ London Birkbeck Coll, London WC1E 7HX, England
[4] Atom Energy Canada Ltd, Chalk River Labs, Chalk River, ON K0J 1J0, Canada
[5] Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada
[6] Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA
[7] Univ Calif Irvine, Dept Phys, Irvine, CA 92717 USA
[8] Carleton Univ, Ottawa, ON K1S 5B6, Canada
[9] Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada
[10] Laurentian Univ, Dept Phys & Astron, Sudbury, ON P3E 2C6, Canada
[11] Univ Calif Berkeley, Lawrence Berkeley Lab, Inst Nucl & Particle Astrophys, Berkeley, CA 94720 USA
[12] Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA
[13] Los Alamos Natl Lab, Los Alamos, NM 87545 USA
[14] Natl Res Council Canada, Ottawa, ON K1A 0R6, Canada
[15] Univ Oxford, Dept Phys, Oxford OX1 3RH, England
[16] Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA
[17] Princeton Univ, Dept Phys, Princeton, NJ 08544 USA
[18] Queens Univ, Dept Phys, Kingston, ON K7L 3N6, Canada
[19] Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England
[20] Univ Sussex, Dept Phys & Astron, Brighton BN1 9QH, E Sussex, England
[21] TRIUMF, Vancouver, BC V6T 2A3, Canada