2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/179086The generalization of the "custodial symmetry" mechanism which leads to the natural (without fine tuning) explanation of the doublet-triplet hierarchy is suggested in the frames of extended $SU(N\geq 8)$ SUSY GUTs. It is shown also that such type of SUSY GUT can predict the value of strong gauge coupling constant $α_S(M_Z)$ consistent with present experimental data.8 pages, latex, 2 latex figures includedHigh Energy Physics - Phenomenologytext