A measurement of D+ and Ds production in e+e- annihilation at √s = 29 GeV

Measurements have been made of the production rates of D+ and Ds mesons via the channels D+ → bar K*0 ell +νell and DS → φπ in e+e- annihilation at √s = 29 GeV in 220 pb-1 of data collected by the Mark II detector. The measurements assume the current branching ratios, measured predominantly at √s ≅ 10 GeV and by fixed target experiments. Measurements of the total production cross-sections times the appropriate branching ratios, which are independent of any other measurements, and an upper limit for the ratio of branching ratios, Γ(Ds) → φπ bar νell/Γ(Ds → φπ) < .74 at 90% confidence level are presented. It is found that the production cross-section of D+ mesons is σ(e+e- → D+X) = .24±.06 ±.04 nb while the production cross-section for DS mesons is σ(e+e- → DsX) =.10±.04±.03 nb. This corresponds to .23±.06 ±.06 D+/hadronic event and .09±.04±.02 Dshadronic event