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

We improve upon previous explicit estimates of charm rescattering contributions to the decay <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:msup><mml:mi>B</mml:mi> <mml:mn>0</mml:mn></mml:msup> <mml:mo>→</mml:mo> <mml:msup><mml:mi>K</mml:mi> <mml:mn>0</mml:mn></mml:msup> <mml:mover><mml:mrow><mml:mi>ℓ</mml:mi></mml:mrow> <mml:mrow><mml:mo>¯</mml:mo></mml:mrow> </mml:mover> <mml:mi>ℓ</mml:mi></mml:mrow> </mml:math> 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 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mmultiscripts><mml:mi>D</mml:mi> <mml:mrow></mml:mrow> <mml:mrow><mml:mo>(</mml:mo> <mml:mrow></mml:mrow> <mml:mo>∗</mml:mo> <mml:mo>)</mml:mo></mml:mrow> </mml:mmultiscripts> <mml:mmultiscripts><mml:mi>D</mml:mi> <mml:mi>s</mml:mi> <mml:mrow><mml:mo>(</mml:mo> <mml:mrow></mml:mrow> <mml:mo>∗</mml:mo> <mml:mo>)</mml:mo></mml:mrow> </mml:mmultiscripts> </mml:mrow> </mml:math> states.