Exclusive Ds semileptonic branching fraction measurements

We measure absolute branching fractions for six exclusive D_s semileptonic decays. We use data collected in the CLEO-c detector from e⁺e^- annihilations delivered by the Cornell Electron Storage Ring with a center-of-mass energy near 4170 MeV. We find B (D_s→ϕ e ν )=(2.14 ±0.17 ±0.08 )% , B (D_s→η e ν )=(2.28 ±0.14 ±0.19 )% , and B (D_s→η^'e ν )=(0.68 ±0.15 ±0.06 )% for the largest modes, where the first uncertainties are statistical and the second are systematic. We also obtain B (D_s→K⁰e ν )=(0.39 ±0.08 ±0.03 )% , B (D_s→K^*e ν )=(0.18 ±0.04 ±0.01 )% , and B (D_s→f₀e ν ,f₀→π π )=(0.13 ±0.03 ±0.01 )% for f₀ masses within 60 MeV of 980 MeV. We use our results to determine the η -η^' and f₀ mixing angles with s s ¯, and we combine our results with lattice calculations to estimate |V_{c s}|. 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.