Production of Charmed Mesons in $e^+ e^-$ Annihilation at 10.5-{GeV}

A measurement is presented of the inclusive production of charged ${D}^{*}$ and neutral $D$ mesons from nonresonant ${e}^{+}{e}^{\ensuremath{-}}$ annihilation in the energy region near the $\ensuremath{\Upsilon}(4S)$ resonance. The momentum distribution shows a large contribution at high momenta as expected for heavy quark production. Comparison of the spectrum with several phenomenological models is made. The relative yields of the ${D}^{*}$ and $D$ mesons indicate that the charm cross section is dominated by the ${D}^{*}$ contribution.