Asymmetric Quark/Antiquark Hadronization in e+e- Annihilation
  We point out that the fragmentation of a strange quark into nucleons versus antinucleons is not necessarily identical $D_{p/s}(z,Q^2) \neq D_{\bar p/s}(z,Q^2)$, even though the perturbative contributions from gluon splitting and evolution are $p \leftrightarrow \bar p$ symmetric. The observation of such asymmetries in the hadronization of strange and other heavy quarks can provide insight into the nonperturbative mechanisms underlying jet fragmentation in QCD. 
S. J. Brodsky and B.-Q. Ma