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

摘要

The decay constant f(sub D(sub s)) of the pseudoscalar strange charm meson D(sub s)(sup +) 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 f(sub B), which is an important number for the measurement of the CKM matrix element V(sub td) in B(sup 0)(bar B)(sup 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(sup -1) of data in e(sup +)e(sup -) collision at (radical)s = 10.58 GeV. In this thesis, these data are searched for e(sup +)e(sup -) (yields) c(bar c) events by identifying sets of charged and neutral pions and charged kaons, consistent with the decay of a charm meson, D(sup 0), D(sup +), D(sub s)(sup +), or D*(sup +). A sample of 510,000 charmed mesons with a momentum consistent with e(sup +)e(sup -) (yields) c(bar c) events is identified.