[1] Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA
[2] Univ Notre Dame, Joint Inst Nucl Astrophys, Notre Dame, IN 46556 USA
[3] Tohoku Univ, Res Ctr Electron Photon Sci, Taihaku Ku, Sendai, Miyagi 9820826, Japan
[4] iThemba Lab Accelerator Sci, ZA-7129 Somerset West, Western Cape, South Africa
[5] Univ Witwatersrand, Sch Phys, ZA-2050 Johannesburg, Gauteng, South Africa
[6] Univ Cape Town, Phys Dept, ZA-7700 Rondebosch, Western Cape, South Africa
[7] Univ Stellenbosch, Dept Phys, ZA-7602 Matieland, Western Cape, South Africa
[8] Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA
[9] Los Alamos Natl Labora, Div Phys, Los Alamos, NM 87545 USA
[10] Katholieke Univ Leuven, Inst Kern Stralingsfys, Celestijnenlaan 200D, B-3001 Leuven, Belgium
[11] Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA