Study ofD/emph>production in high-energyγpinteractions

We have studied $D^{\mathrm{*}}$ production mechanisms using data from a photoproduction experiment at the Fermilab Tagged Photon Spectrometer. A large sample of charged $D^{\mathrm{*}}$’s was selected via the clean signature of the cascade decay $D^{\mathrm{*}}$→$D^0$ ${\pi }^{+}$ and subsequently $D^0$→$K^{\mathrm{-}}$ ${\pi }^{+}$ or $D^0$→$K^{\mathrm{-}}$ ${\pi }^{+}$ ${\pi }^0$. The cross section for the process γp→($D^{\mathrm{*}+}$+anything)p at an average energy of 105 GeV was measured to be 88±32 nb. Only (11±7)% of $D^{\mathrm{*}}$’s were found to be consistent with being accompanied solely by a D${¯}^{\mathrm{*}}$ or a D¯; the remaining events contain additional particles. The distribution of the production angle of the $D^{\mathrm{*}}$ in the photon-fragmentation-system center of mass is strongly anisotropic and consistent with the form f(${\theta }^{\mathrm{*}}$)=${\cos }^4$ ${\mathrm{\theta }}^{\mathrm{*}}$. We set a limit on the associated-production-process cross section σ(γp→(D${¯}^{\mathrm{*}\mathrm{-}}$+anything)${\Lambda }_c$) x)