A Measurement of the Pseudoscalar Decay Constant fDs using Charm-Tagged Events in e+e- Collisions at the Y(4S)

The decay constant fD#sub s# of the pseudoscalar strange charm meson Ds+ is an important benchmark test of the theoretical methods that quantitatively describe the nonperturbative low-energy regime of QCD, the theory of the strong interaction. A confirmation of the validity of these predictive methods, foremost lattice QCD, in the sector of heavy-light meson decay constants increases trust in the calculation of fB, which is an important number for the measurement of the CKM matrix element Vtd in B0(bar B)0-mixing events. From October 1999 through July 2004, the BABAR experiment, located at the PEP-II storage ring at the Stanford Linear Accelerator Center, collected 230.2 fb-1 of data in e+e- collision at √s = 10.58 GeV. In this thesis, these data are searched for e+e- → c(bar c) events by identifying sets of charged and neutral pions and charged kaons, consistent with the decay of a charm meson, D0, D+, Ds+, or D*+. A sample of 510,000 charmed mesons with a momentum consistent with e+e- → c(bar c) events is identified