zacekv@lps.umontreal.ca

¹ Département de Physique, Université de Montréal, Montréal, H3C 3J7, Canada
² Department of Physics, University of Alberta, Edmonton, T6G 2G7, Canada
³ Department of Physics and Astronomy, Indiana University South Bend, South Bend, IN 46634, USA
⁴ Department of Physics, Laurentian University, Sudbury, P3E 2C6, Canada
⁵ Institute of Experimental and Applied Physics, Czech Technical University in Prague, Prague, Cz-12800, Czech Republic
⁶ Department of Physics, Queens University, Kingston, K7L 3N6, Canada
⁷ Present address: Department of Physics, McGill University, Montréal, H3A 2T8, Canada.
⁸ Present address: Institut de Physique, Université de Neuchâtel, CH-2000, Neuchâtel, Switzerland.
⁹ Present address: Fakultät für Physik, Ludwig-Maximilians-Universität, D-85748 Garching, Germany.
¹⁰ Present address: Centro de Física Nuclear, Universidade de Lisboa, 1649-003, Portugal.
¹¹ Present address: Department of Physics, Case Western Reserve University, Cleveland OH 44106-7079, USA.
¹² Author to whom any correspondence should be addressed.