$S$-wave $K\pi$ contributions to the hadronic charmonium $B$ decays in the perturbative QCD approach

We extend our recent works on the two-pion $S$-wave resonance contributions to the kaon-pion ones in the $B$ meson hadronic charmonium decay modes based on the perturbative QCD approach. The $S$-wave $K\pi$ time-like form factor in its distribution amplitudes is described by the LASS parametrization, which consists of the $K_0^{\ast }(1430)$ resonant state together with an effective range nonresonant component. The predictions for the decays $B\rightarrow J/\psi K\pi$inthisworkagreewellwiththeexperimentalresultsfrom$BABAR$ and Belle Collaborations. We also discuss theoretical uncertainties, indicating the results of this work, which can be tested by the LHCb and Belle-II experiments, are reasonably accurate.