Comparison of kaon and pion valence quark distributions in a statistical   model
  We have calculated the Bjorken-x dependence of the kaon and pion valence quark distributions in a statistical model. Each meson is described by a Fock state expansion in terms of quarks, antiquarks and gluons. Although Drell-Yan experiments have measured the pion valence quark distributions directly, the kaon valence quark distributions have only been deduced from the measurement of the ratio $\bar{u}_K(x)/\bar{u}_\pi(x)$. We show that, using no free parameters, our model predicts the decrease of this ratio with increasing x. 
Mary Alberg and Jeffrey Tibbals
nucl-th hep-ph