Parton distributions

Downloading files

  • The CJ15 next-to-leading order (NLO) PDFs can be obtained by downloading the CJpdf.f Fortran file and the CJ15 NLO error grids, together with an example program which calls the PDFs.
  • A leading order (LO) CJ15 fit is also available, with the corresponding LO error grids.
  • The grids from the earlier CJ12 NLO analysis are available, for the CJ12min, CJ12mid and CJ12max sets, although these have been superceded by the CJ15 PDFs.
  • The CJ15 PDFs are also included in the newest LHAPDF distribution.


  • The program gives PDFs in the range 10-6 ≤ x ≤ 1 and 1.3 ≤ Q ≤ 105 GeV. However, the region where the PDFs are directly constrained by data is 2 x 10-5 < x < 0.9 and 1.3 < Q < 550 GeV.
  • When using the PDFs, please refer to the following reference:
    A. Accardi, L. T. Brady, W. Melnitchouk, J. F. Owens and N. Sato, arXiv:1602.03154, to appear in Phys. Rev. D (2016)
  • Please contact Alberto Accardi with any questions at "".