Measurement of the Decays $\mathbf{B}\to \mathbf{\eta }\mathbf{\ell }{\mathbf{\nu }}_{\mathbf{\ell }}$ and $\mathbf{B}\to {\mathbf{\eta }}^{\prime }\mathbf{\ell }{\mathbf{\nu }}_{\mathbf{\ell }}$ in Fully Reconstructed Events at Belle

Belle Collaboration, C. Beleño, J. Dingfelder +142

We report branching fraction measurements of the decays $B^{+}\to \eta {\ell }^{+}{\nu }_{\ell }$ and $B^{+}\to {\eta }^{\prime }{\ell }^{+}{\nu }_{\ell }$ based on 711~fb${}^{-1}$ of data collected near the ${\rm Y}(4S)$ resonance w…