2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/45909The contribution of interactions at short and large distances to particle masses is discussed in the framework of the standard model.9 pages, LaTex, 11 figures (pictex) in separate file. Opening lecture given at the 33rd course of the International School of Subnuclear Physics, Erice, Sicily (1995)High Energy Physics - Phenomenologytext