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

Abstract We improve upon previous explicit estimates of charm rescattering contributions to the decay $$B^0\rightarrow K^0{\bar{\ell }}\ell $$ B 0 → K 0 ℓ ¯ ℓ 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 $$D^{(*)}D^{(*)}_s$$ D ( ∗ ) D s ( ∗ ) states.