The hidden charm decay of X(3872),Y(3940)X(3872),Y(3940) and final state interaction effects

We investigate whether the final state interaction (FSI) effect plays a significant role in the large hidden charm decay width of X(3872)X(3872) and Y(3940)Y(3940) using a model. Our numerical result suggests (1) the FSI contribution to X(3872)→J/ψρX(3872)→J/ψρ is tiny; (2) Γ[Y(3940)→DD¯∗+h.c.→J/ψω] from FSI is around several keV, far less than Belle's experimental value 7 MeV.