Measurements of Total Hadronic and Inclusive D - Cross-Sections in Electron Positron Annihilation Between 3.87 and 4.5 Giga-Electron Volts.

Results are presented on measurements of two inclusive hadron cross sections in electron-positron annihilation at center of mass energies in the resonance region (3.87 -4.5 Gev) above open charm threshold. The measurements were made using the Crystal Ball detector in the SPEAR storage ring facility at the Stanford Linear Accelerator Center. The first result presented is a high statistics measurement of the total hadronic cross section, which displays the center of mass energy behavior of charm production. An additional data point at 3.67 Gev allows a comparison to energies below open charm threshold. The shape of the cross section consists of a resonance at 4.03 Gev, a broader peak at 4.4 Gev, a broad shoulder near 4.16 Gev, and a valley above 4.2 Gev. This shape generally agrees with previous measurements, with differences in the overall normaliza- tion and the structure near 4.16 Gev. The second result presents pizero kinetic energy spectra at the (psi)''(3.772) and energies between 3.87 and 4.5 Gev. D* production is associated with a low energy peak in the pizero kinetic energy spectrum (below 50 Mev) arising from D* (--->) (pi)('0)D cascade decays. The excess number of slow pizeros is used to calculate the inclu- sive cross section for producing D* mesons in electron -positron collisions. The shape of this cross section is qualitatively similar to the total hadronic cross section. The results agree well with previous experimental data and with a phenomenological potential model. The two results are combined to yield the average number of D* mesons per charm event. This number, approximately 1 between D*(')D and D*(')D* threshold and 1.5-2 at higher energies, places constraints upon models attempting to explain the behavior of the charm cross section in this energy region.