2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/189366We investigate whether the final state interaction (FSI) effect plays a significant role in the large hidden charm decay width of X(3872) and Y(3940) using a model. Our numerical result suggests (1) the FSI contribution to $X(3872)\to J/ψρ$ is tiny; (2) $Γ[ Y(3940)\to D\bar{D}^{*}+\text{h.c.}\to J/ψω]$ from FSI is around several keV, far less than Belle's experimental value 7 MeV.5 pages, 3 figures, 1 table. Version to appear in Physics Letters BHigh Energy Physics - PhenomenologyHigh Energy Physics - Experimenttext