[1] CERN, Helsinki Inst Phys, CH-1211 Geneva, Switzerland
[2] Univ Helsinki, Helsinki Inst Phys, Helsinki 00014, Finland
[3] LIP, P-1000 Lisbon, Portugal
[4] Vilnius State Univ, Inst Mat Sci & Appl Res, LT-2040 Vilnius, Lithuania
[5] Univ Naples Federico II, Dipartimento Fis, I-80125 Naples, Italy
[6] Ist Nazl Fis Nucl, I-80125 Naples, Italy
[7] Univ Karlsruhe, IEKP, D-76128 Karlsruhe, Germany
[8] Univ Florence, Dipartimento Energet, I-50139 Florence, Italy
[9] Univ Bern, Lab Hochenergiephys, CH-3012 Bern, Switzerland
[10] Brookhaven Natl Lab, Upton, NY 11973 USA
[11] Jozef Stefan Inst, Exp Particle Phys Dept, Ljubljana 1001, Slovenia
[12] Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia
[13] Brunel Univ, Uxbridge UB8 3PH, Middx, England
[14] Univ Geneva, Dept Radiol, Geneva, Switzerland
[15] ILK Dresden, D-01309 Dresden, Germany
[16] Univ Turku, Wihuri Phys Lab, Turku 20014, Finland
[17] Tech Univ Munich, Phys Dept E18, D-85748 Garching, Germany
[18] Catholic Univ Louvain, B-1348 Louvain, Belgium
[19] Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland