CLEO Collaboration, T. K. Pedlar
Published 2007-04-03, updated 2007-08-16Version 3
We examine e+e- --> Ds- Ds*+ and Ds*- Ds+ interactions at 4170 MeV using the CLEO-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)%. We also 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 the ratio fDs/fD+ = 1.23 +- 0.11 +- 0.04. We compare to current theoretical estimates. Finally, we find B(Ds+ --> e+ nu) < 1.3 x10^{-4} at 90% confidence level.
Comments: 24 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2007/, Submitted to PRD
Journal: Phys.Rev.D76:072002,2007
Search for B^0 -> l^+ l^- at Belle
Structure Functions in the Decay $τ^{\mp}\to τ^{\mp}π^{0}π^{0}ν_τ$
Search for Decays of B^{0} Mesons into Pairs of Leptons: B{0} -> e^{+}e^{-}, B^{0} -> μ^{+}μ^{-} and B^{0} -> e^{\pm}μ^{\mp}
![QR code for arXiv:0704.0437 [hep-ex]](http://oss.arxitics.com/images/favicon.svg)