2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/186817We present an exact method to study four-quark systems based on the hyperspherical harmonics formalism. We apply it to several physical systems of interest containing two heavy and two light quarks using different quark-quark potentials. Our conclusions mark the boundaries for the possible existence of compact, non-molecular, four-quark bound states. While $QQ\bar n \bar n$ states may be stable in nature, the stability of $Q\bar Qn \bar n$ states would imply the existence of quark correlations not taken into account by simple quark dynamical models10 pages, 1 figure. Accepted for publication in Phys. Rev. DHigh Energy Physics - PhenomenologyHigh Energy Physics - ExperimentNuclear Theorytext