Representing the SLD Collaboration

Using hadronic ZO decays recorded by the SLD experiment at SLAC, we have measured the vector/ (vector+pseudoscalar) production ratio, V/(V + P), for the prompt charmed mesons, D*+ and D+ Using the channels D*+ ~ D“n$ , Do + Ii–T+, and Do _ li-–T~n–T~ , as well as D+ ~ Ii’– T~T– , we f ind V/(V + P) = 0.61 + 0.09( .stat.) + 0.03(BR), which disfavors the expectation of 0.75 from naive spin-counting. We have also measured the degree of D*+ spin alignment along the flight direction and find it to be consistent with zero for D*+ fractional momenta x ❑ II;[). /E~e,,~ > 0.2. We compare these results with QCD model predictions, *This work was supported by Departmcnt of Energy contract: DE-AC03-76SF00515 (SLAC) Presented at the annual Divisional Meeting (DPF 96) of the Division of Particles and Fields of the American Physical Society, 10-15 August 1996, Minneapolis, MN.