B(Ds^+ -> l^+ nu) and the Decay Constant f_(D_s^+)

Abstract

I report final CLEO-c results on the purely leptonic decays of the D_s^+ -> l^+ nu, for the cases when l^+ is a mu^+ or tau^+, when it decays into pi^+ anti-nu, using 314/pb of data at 4.170 GeV. I also include preliminary results from the tau^+ -> e^+ nu anti-nu channel using 195/pb. Combining both we measure f_{D_s}= 275 +/- 10 +/- 5 MeV, and f_{D_s^+}/{f_{D^+}=1.24 +/- 0.10 =/- 0.03 .

Presented at "The 2007 Europhysics Conference on High Energy Physics," Manchester, England, 19-25 July 2007, to appear in the proceedings. Three pages, 1 figure