ExclusiveDssemileptonic branching fraction measurements

Abstract

We measure absolute branching fractions for six exclusive ${D}_{s}$ semileptonic decays. We use data collected in the CLEO-c detector from ${e}^{+}{e}^{\ensuremath{-}}$ annihilations delivered by the Cornell Electron Storage Ring with a center-of-mass energy near 4170 MeV. We find $\mathcal{B}({D}_{s}\ensuremath{\rightarrow}\ensuremath{\phi}e\ensuremath{\nu})=(2.14\ifmmode\pm\else\textpm\fi{}0.17\ifmmode\pm\else\textpm\fi{}0.08)%$, $\mathcal{B}({D}_{s}\ensuremath{\rightarrow}\ensuremath{\eta}e\ensuremath{\nu})=(2.28\ifmmode\pm\else\textpm\fi{}0.14\ifmmode\pm\else\textpm\fi{}0.19)%$, and $\mathcal{B}({D}_{s}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}e\ensuremath{\nu})=(0.68\ifmmode\pm\else\textpm\fi{}0.15\ifmmode\pm\else\textpm\fi{}0.06)%$ for the largest modes, where the first uncertainties are statistical and the second are systematic. We also obtain $\mathcal{B}({D}_{s}\ensuremath{\rightarrow}{K}^{0}e\ensuremath{\nu})=(0.39\ifmmode\pm\else\textpm\fi{}0.08\ifmmode\pm\else\textpm\fi{}0.03)%$, $\mathcal{B}({D}_{s}\ensuremath{\rightarrow}{K}^{*}e\ensuremath{\nu})=(0.18\ifmmode\pm\else\textpm\fi{}0.04\ifmmode\pm\else\textpm\fi{}0.01)%$, and $\mathcal{B}({D}_{s}\ensuremath{\rightarrow}{f}_{0}e\ensuremath{\nu},{f}_{0}\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\pi})=(0.13\ifmmode\pm\else\textpm\fi{}0.03\ifmmode\pm\else\textpm\fi{}0.01)%$ for ${f}_{0}$ masses within 60 MeV of 980 MeV. We use our results to determine the $\ensuremath{\eta}\ensuremath{-}{\ensuremath{\eta}}^{\ensuremath{'}}$ and ${f}_{0}$ mixing angles with $s\overline{s}$, and we combine our results with lattice calculations to estimate $|{V}_{cs}|$. This measurement improves upon the ${D}_{s}$ semileptonic branching ratio precision and provides a new approach for future work that eliminates the ${D}_{s}^{*}$ daughter photon reconstruction.