${\eta }^{(\prime )}$ productions in semileptonic B decays

Abstract

Inspired by the new measurements on $B^{-}\to {\eta }^{(\prime )}\ell {\bar{\nu }}_{\ell }$ from the BaBar Collaboration, we examine the constraint on the flavor-singlet mechanism, proposed to understand the large branching ratios for $B\to {\eta }^{\prime }K$ decays. Based on the mechanism, we study the decays of ${\bar{B}}_{d,s}\to {\eta }^{(\prime )}{\ell }^{+}{\ell }^{-}$ and find that they are sensitive to the flavor-singlet effects. In particular, we show that the decay branching ratios of ${\bar{B}}_{d,s}\to {\eta }^{\prime }{\ell }^{+}{\ell }^{-}$ can be as large as $O(10^{-8})$ and $O(10^{-6})$, respectively.

Comments: 10 pages, 2 figures, final version to appear in Phys. Lett. B