2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/212862The phenomenology of gluon saturation at small parton momentum fraction, Bjorken-x, in the proton and in the nucleus is introduced. The experimentally-accessible kinematic domains at the nucleus-nucleus colliders RHIC and LHC are discussed. Finally, the saturation hints emerging from measurements at RHIC and the perspectives for LHC are described.6 pages, 4 figures, prepared for the proceedings of ISMD 08High Energy Physics - Phenomenologytext