Forward-backward asymmetry of B → KJ l+l − decays in SM and new physics models

We report on our studies of B → KJ l+l − in the standard model and several new physics variations, with KJ denoting a kaonic resoanance. In terms of helicity amplitudes, we derive a compact form for the full angular distributions, and use them to calculate the branching ratios, forward-backward asymmetries and polarizations. We have updated the constraints on effective Wilson coefficients and/or free parameters in these new physics scenarios by making use of the B → K∗l+l − and b → sl+l − experimental data. Their impact on B → K∗J l+l − is subsequently explored and in particular the zero-crossing point for forward-backward asym-metry in new physics scenarios can sizably deviate from the standard model.