English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We examine e+e- --> Ds- Ds*+ and Ds*- Ds+ interactions at 4170 MeV using theCLEO-c detector in order to measure the decay constant fDs+. We use the Ds+ -->l+ nu channel, where the l+ designates either a mu+ or a tau+, when the tau+--> pi+ nu. Analyzing both modes independently, we determine B(Ds+ --> mu+ nu)= (0.594 +- 0.066 +- 0.031)%, and B(Ds+ --> tau+ nu) = (8.0 +- 1.3 +- 0.4)%. Wealso analyze them simultaneously to find an effective value of B{eff}(Ds+ -->mu+ nu) = (0.638 +- 0.059 +- 0.033)% and extract fDs = (274 +- 13 +- 7) MeV.Combining with our previous determination of B(D+ -> mu+ nu), we also find theratio fDs/fD+ = 1.23 +- 0.11 +- 0.04. We compare to current theoreticalestimates. Finally, we find B(Ds+ --> e+ nu) < 1.3 x10^{-4} at 90% confidencelevel.

Measurement of B(D_S^+ --> ell^+ nu) and the Decay Constant f_D_{S^+}