Study B→a ₁(1260)(b ₁(1235))η ^(′) decays in the PQCD approach

Abstract

By using the decay constants and light-cone distribution amplitudes derived from QCD sum-rule method, we calculate the branching ratios of decays B→a ₁(1260)η ^(′) and B→b ₁(1235)η ^(′) in the PQCD factorization approach and find that the charged decays $B^{-}\to a^{-}_{1}(1260)\eta^{(\prime)}$ have larger branching ratios, which are at the order of $\mathcal{O}(10^{-6})$, for receiving large contributions from the factorizable emission diagram amplitudes and large decay constant $f_{a_{1}}=238\pm10~\mathrm{MeV}$ compared with $f_{b_{1}}$. For the other decays, their branching ratios are at the order of $\mathcal{O}(10^{-7})$ when the η meson is involved, and $\mathcal{O}(10^{-8})$ when the η′ meson is involved. For all of the considered decays, the branching ratios of the channels involved η meson are larger than those of the channels involved η′ meson. We also predict the direct, mixing-induced, and total CP-violating asymmetries of the relevant decays.