Physics Letters B, 345, 93-102. Elsevier science bv Physics Letters B, 345, 1, pp. 93-102 SEDICI (UNLP) Universidad Nacional de La Plata instacron:UNLP Physics Letters B Meeting of the Division of Particles and Fields of the American Physical Society-DPF '94 8 Meeting of the Division of Particles and Fields of the American Physical Society-DPF '94 8, Aug 1994, Albuquerque, United States. pp.93-102 Physics Letters B, 345. Elsevier