2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/173089In the framework of coupled-channel formalism the relativistic four-quark equations are found. The dynamical mixing of the meson-meson states with the four-quark states is considered. The four-quark amplitudes of the tetraquarks with open charm, including u, d, s, c quarks, are constructed. The poles of these amplitudes determine the masses and widths of tetraquarks.8 pages, latexHigh Energy Physics - PhenomenologyHigh Energy Physics - Experimenttext