2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/41506The purpose of this paper is to answer the following question : is it possible to find a gauge group G and a space-time dimension D such that anomalies constrain the fermion content to be composed of the 3 known families of quarks and leptons ? The answer is, in some way, unique and consists in taking an SU(5) gauge group in 6 dimensions. This work has been done with the collaboration of N. Borghini and M. H. Tytgat.6 pages, 1 figure, to appear in proceedings of Rencontres de Moriond 'Electroweak interactions and unified theories 2002'High Energy Physics - Phenomenologytext