Violation of the Feynman scaling law as a manifestation of   nonextensivity
  We demonstrate that the apparently ad hoc parametrization of the particle production spectra discussed in the literature and used in description of cosmic ray data can be derived from the information theory approach to multiparticle production processes. In particular, the violation of the Feynman scaling law can be interpreted as a manifestation of nonextensivity of the production processes. 
F.S.Navarra, O.V.Utyuzh, Z.Wlodarczyk and G.Wilk