Estimates for forward-backward asymmetry in B → K∗ (892) l+l−

Forward-backward charge asymmetry in rare dilepton B-decays is formulated with the assumption of an on-shell b-quark. We find that the asymmetry is expressed in terms of two spatially transverse helicity amplitudes, which are determined by combining the data of D → K∗ (892) l+ν with heavy flavour symmetry. We estimate the charge asymmetry of B → K∗ (892) l+l− for large energy leptons against various top masses in the standard model.