Studies of $D{ \bar D}$ correlations for a large sample of events containing fully and partially reconstructed pairs of charmed $D$ mesons recorded by the Fermilab photoproduction experiment FOCUS (FNAL-E831) are presented. Correlations between $D$ and ${ \bar D}$ mesons are used to study heavy quark production dynamics. We present results for fully and partially reconstructed charm pairs and comparisons to a recent version of \textsc{ Pythia} with default parameter settings. We also comment on the production of $\psi(3770)$ in our data.
Categories: hep-ex