Form factors, branching ratio and forward-backward asymmetry in B -> K_{1}ell ^{+} ell ^{-} decays

Abstract

We study long-distance effects in rare exclusive semileptonic decays B -> K_{1}ell ^{+}ell ^{-}, K_{1} is the axial vector meson.The form factors, describing the meson transition amplitudes of the effective Hamiltonian, are calculated using Ward identites which are then used to calculate branching ratio and forward-backward asymmetry in these decay modes. The zero of forward-backward asymmetry is of special interest and provide us the precission test of Standard model.