Branching ratios, forward-backward asymmetries, and angular distributions of B→K2*l+l- in the standard model and two new physics scenarios

We analyze the B→K2*(→Kπ)l+l- (with l=e, μ, τ) decay in the standard model and two new physics scenarios: the vectorlike quark model and family nonuniversal Z' models. We derive the differential angular distributions using the recently calculated form factors in the perturbative QCD approach. Branching ratios, polarizations, forward-backward asymmetries, and transversity amplitudes are predicted, from which we find a promising prospective to observe this channel in future experiments. We update the constraints on effective Wilson coefficients and/or free parameters in these two new physics scenarios by making use of the B→K*l+l- and b→sl+l- experimental data. Their impact on B→K2*l+l- is subsequently explored and, in particular, the zero-crossing point for the forward-backward asymmetry in these new physics scenarios can sizably deviate from the standard model. In addition we also generalize the analysis to a similar mode, Bs→f2'(1525)(→K+K-)l+l-.