By using the 3-point QCD sum rules, we calculate the transition form factors of [Formula: see text] decays into the spin triplet axial vector mesons [Formula: see text], [Formula: see text], [Formula: see text]. In the calculations, we consider the quark contents of each meson in detail. In view of the fact that the isospin of [Formula: see text] is one, we calculate the [Formula: see text] and [Formula: see text] transition form factors separately. In the case of [Formula: see text], [Formula: see text], the mixing between light flavor [Formula: see text] singlet and octet is taken into account. Based on the form factors obtained here, we give predictions for the branching ratios of relevant semileptonic decays, which can be tested in the future experiments.
Branching ratios of theBcmeson decaying to pseudoscalar and axial-vector mesons
