[1] UNIV MICHIGAN, RANDALL LAB PHYS, ANN ARBOR, MI 48104 USA
[2] MAX PLANCK INST PHYS, D-8000 MUNICH 40, BUNDES REPUBLIK
[3] NIELS BOHR INST, DK-2100 COPENHAGEN, DENMARK
[4] CERN, CH-1211 GENEVA, SWITZERLAND
[5] ARGONNE NATL LAB, DIV ACCELERATOR RES FACIL, ARGONNE, IL 60439 USA
[6] ST LOUIS UNIV, DEPT PHYS, ST LOUIS, MO 63103 USA