Charged $D^{*}$ Production in $e^{+}{e}^{-}$ Annihilation at 29 GeV and a Limit on $D^0-{\overline{D}}^0$ Mixing

We have studied inclusive $D^{*\pm }$ production using the DELCO detector at PEP. Our technique involved kaon identification in the momentum range above 3.2 GeV/c using a threshold gas Čerenkov counter. This leads to a model-independent upper limit on $D^0-{\overline{D}}^0$ mixing of 8.1% (90% confidence level). We also have measured the charm fragmentation function, which peaks at $x\equiv \frac{P_{D^{*}}}{{(E_{\mathrm{beam}}^2-M_{D^{*}}^2)}^{\frac{1}{2}}}$ of 0.56±0.06(stat.), and the total cross section for $D^{*}$ production, $\sigma \left(D^{*\pm }\right)=0.140\mathrm{}\pm 0.021(\mathrm{stat}.\mathrm{})\pm 0.032(\mathrm{syst}.\mathrm{})$ nb ($x>\mathrm{}0.3\mathrm{}$, with radiative correction).