Nonfactorizable effects in B to charmonium decays

Nonleptonic $B$ to charmonium decays generally deviate from the factorization predictions. We study rescattering effects mediated by intermediate charmed mesons in this class of decay modes and, in particular, we consider $B^{-}\to K^{-}{h}_c$ with $h_c$ the $J^{PC}=1^{+-}$ $\bar{c}c$ meson, relating this mode to $B^{-}\to K^{-}{\chi }_{c0}$. We find $\mathcal{B}(B^{-}\to K^{-}{h}_c)$ large enough to be measured at the $B$ factories, hence this process could be used to study the poorly known $h_c$.