Multiple Charged Meson Production in Exclusive $B_{c}$ Decays: $K+4\pi,$$KK+3\pi$, $7\pi$ Cases

Theoretical analysis of three exclusive decays, $B_{c}\to J/\psi+\mathcal{R},$where $\mathcal{R}=K+4\pi,$$KK+3\pi$, or $7\pi$, is given. Using the factorization method and the resonance approximation (methods proved to be very useful in the analysis of some other similar decays), we have obtained analytical expressions of the required amplitudes and created distributions over some interesting mass combinations. Presented results could be used for comparison with forthcoming experimental data and better understanding of the nature of heavy quarkonia.