Improved Parameterization of $K^+$ Production in p-Be Collisions at Low   Energy Using Feynman Scaling
  This paper describes an improved parameterization for proton-beryllium production of secondary $K^{+}$ mesons for experiments with primary proton beams from 8.89 to 24 GeV. The parameterization is based on Feynman scaling in which the invariant cross section is described as a function of $x_{F}$ and $p_{T}$. This method is theoretically motivated and provides a better description of the energy dependence of kaon production at low beam energies than other parameterizations such as the commonly used "Modified Sanford-Wang" model. This Feynman scaling parameterization has been used for the simulation of the neutrino flux from the Booster Neutrino Beam (BNB) at Fermilab and has been shown to agree with the neutrino interaction data from the SciBooNE experiment. This parameterization will also be useful for future neutrino experiments with low primary beam energies, such as those planned for the Project X accelerator. 
C. Mariani, G. Cheng, J.M. Conrad, M.H. Shaevitz
hep-ex hep-ph