“…In the recent years, the intermediate meson loop is investigated in a lot of meson decay channels [8,9,10,11,12,13,14,15,16] as one of the important non-perturbative transition mechanisms, or known as final state interactiions (FSI). In particular in the energy region of charmonium masses, with more and more data from Belle, BaBar, CLEO-c and BES, it is widely studied that intermediate meson loop may account for apparent OZI-rule violations [11,12,13,14,15,16] via quark-hadron duality arguement [17,18,19].…”