Form Factors of B_(u,d,s) Decays into P-Wave Axial-Vector Mesons in the Light-Cone Sum Rule Approach

We calculate the vector and axial-vector form factors of $B_{u,d,s}$ decays into P-wave axial-vector mesons in the light-cone sum rule approach. For the sum rule results, we have included corrections of order $m_A/m_b$, where $m_A$ is the mass of the axial-vector meson $A$. The results are relevant to the light-cone distribution amplitudes of the axial-vector mesons. It is important to note that, owing to the $G$-parity, the chiral-even two-parton light-cone distribution amplitudes of the $^3P_1$ ($^1P_1$) mesons are symmetric (antisymmetric) under the exchange of quark and anti-quark momentum fractions in the SU(3) limit. For chiral-odd light-cone distribution amplitudes, it is the other way around. The predictions for decay rates of $B_{u,d,s} \to A e \nu_e$ are also presented.