Asymmetries in {\bar B}_d^0 -> {\bar K}^{*0} e+ e- decay and contribution of vector resonances

Abstract

The fully differential angular distribution for the rare flavor-changing neutral current decay {\bar B}_d^0 -> {\bar K}^{*0} (-> K^- \pi^+) e+ e- is studied. The emphasis is placed on accurate treatment of the contribution from the processes \bar{B}_d^0 -> \bar{K}^{*0} (-> K^- pi^+) V with intermediate vector resonances V = \rho(770), \omega(782), \phi(1020), J/\psi, \psi(2S), ... decaying into the e+ e- pair. The two versions of the vector-meson-dominance model for the transition V \gamma are used and tested. The present method of including vector resonances is also compared with the existing in the literature method. The electron-positron invariant mass dependence of the branching ratio and various asymmetries is calculated. The branching ratio, longitudinal polarization fraction of the {\bar K}^{*0} meson, transverse asymmetry A_T^{(2)} and forward-backward asymmetry are compared with data from Belle and CDF, and predictions for experiments at LHCb are made.