Charm Production in e+e- Annihilation
The cross sections for charm production in continuum e+e- annihilation near 10 GeV and near 30 GeV are presented. With the latest values for the D-meson decay branching ratios, about 70% of the charm quarks end up in the D° or D± mesons. There is no evidence for a charm deficit. The relative production of the vector and pseudoscalar mesons is in accord with the expectations of spin counting. Measurements of the D decay angular distribution show that the vector mesons are primarily produced with equal populations in all helicity states, although there is some evidence for D alignment for the highest D* momenta in the 10 GeV data.
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