Statistical model for pionic partons
  We present a model for the structure of the pion. Based on ideas of a recently developed statistical model of the nucleon, we assume the pion to be a gas of partons. The finite-size corrections (FSC) are incorporated through two parameters. Using the same two FSC parameters for the proton and pion we reproduce quantitatively the data on $\pi^- N \to \mu^+ \mu^- X$ Drell-Yan production and valence quark distribution of the pion. 
N. G. Kelkar and M. Nowakowski