A simple approach to describe hadron production rates in $e^+ e^-$   annihilation
  We show that, based on the idea of string fragmentation, the production rates of light flavored mesons and baryons originating from fragmentation can be described by the spin, the binding energy of the particle, and a strangeness suppression factor. Apart from a normalization factor, $e^+ e^-$ data at different center-of-mass energies can be described simultaneously. Applying to the heavy flavor production, we find that our predictions are in good agreement with data. 
Yi-Jin Pei