Charm rescattering in $B^0\to K^0\bar{\mathrm{\ell }}\mathrm{\ell }$: an improved analysis

We improve upon previous explicit estimates of charm rescattering contributions to the decay $B^0\to K^0\bar{\mathrm{\ell }}\mathrm{\ell }$ by including contributions from dipole interactions with the intermediate charm-meson states, and by further investigating the structure of the electromagnetic form factors. Using a model of fundamental meson fields inspired by heavy-hadron chiral perturbation theory, augmented by form factors motivated by theoretical considerations as well as experimental data, we provide a thorough investigation of rescattering contributions induced by intermediate $D^{(\ast )}{D}_s^{(\ast )}$ states.