Study of Semileptonic Decays $B^\pm \to η^{(\prime)} l ν$

Abstract

We study semileptonic decays $B^\pm \to η^{(\prime)} l ν$, which are suggested to be used to extract the hadronic form factors of $B$ meson decays to $η(η^{\prime})$ and the angle of $η-η^{\prime}$ mixing. This would be of great benefit to theoretical studies of $B$ nonleptonic decays involving $η$ and $η^{\prime}$, and could lead to a reliable and complementary determination of $V_{ub}$. The branching ratios are estimated to be ${\cal B}(B^\pm \toη^{(\prime)} l ν)=4.32 \pm 0.83 (2.10 \pm 0.40) \times 10^{-5}$, which could be extensively studied experimentally at $BaBar$ and Belle.