2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/203949We study an extension of the MSSM with a fourth generation of chiral matter. With this extension no value of $\tb$ allows the theory to stay perturbative up to the GUT scale. We suggest one model with extra vector-like states at the TeV scale that allows perturbativity all the way up to the GUT scale.12 pages, 4 figuresHigh Energy Physics - Phenomenologytext