Additional contributions by Sheldon Lee Glashow, Donald H. Perkins, and Antonino Pullia S. L. Glashow, D. H. Perkins and A. Pullia Eur. Phys. J. C, 34 1 (2004) 103-105 Published online: 04 May 2004 DOI: 10.1140/epjc/s2004-01773-9