Semileptonic B(s )→α1(K1)ℓ+ℓ- decays via the light-cone sum rules with B -meson distribution amplitudes

The form factors of semileptonic B_{(s )}→a₁(K₁)ℓ⁺ℓ^- , ℓ=τ , μ , e transitions are investigated in the framework of the light-cone sum rules with B -meson distribution amplitudes, which play an important role in exclusive B decays. The B -meson distribution amplitudes, φ_±(ω ) are a model-dependent form, so we consider four different parametrizations which can provide a reasonable description of φ_±(ω ) from QCD corrections. The branching fractions of these transitions are calculated. For a better analysis, a comparison of our results with the prediction of other models is provided.