  A simple extension of the QCD inspired potential model which includes
dynamical quarks first proposed by Eichten et al. is remarkably successful in
accounting both for the observed narrow state heavy quarkonium spectroscopy and
experimental data on threshold production of charmed and B mesons in e+e-
annihilation. In addition to this model, a variant of it can also account for
the data. The cross section data are mainly inclusive cross section
measurements. The two models give distinguishably different predictions for the
energy dependence of production cross sections for individual channels, and
measurment of the energy dependence of production cross sections for individual
channels may distinguish between these models.
