2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/220244We analyze a contribution of the finite-width (mass-smearing) effects to the mixing of neutral mesons. It was shown, that this contribution is dominant in the D-meson system and large in the K-meson one. An account of the mass-smearing effects allows to explain some discrepancy between standard predictions and experimental data in these cases.16 pages, 5 figures, 1 tableHigh Energy Physics - Phenomenologytext