EHKQS

EHKQS nonlinear parton distributions

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These are the nonlinear parton distribution sets created in

K.J. Eskola, H. Honkanen, V.J. Kolhinen, J.w. Qiu and C.A. Salgado, “Nonlinear corrections to the DGLAP equations in view of the HERA data,” Nucl. Phys. B 660 (2003) 211 [arXiv:hep-ph/0211239].

by using the DGLAP+GLRMQ evolution, and the CTEQ5L and CTEQ6L sets at large (Q^2,x) as a baseline. Please refer to the above article when using these PDF sets.

Package EHKQSsets.tar.gz contains three data files, a setup/interpolation routine and a simple example program.

The three sets, p-set1table.dat, p-set2atable.dat and p-set2btable.dat employ the initial scale Q_0^2=1.4 GeV^2 and \Lambda_{QCD}=0.192 GeV for four flavors. They differ in the treatment of the charm mass threshold in the evolution:

  • In set 1 (p-set1table.dat) there is a nonzero charm distribution at the initial scale Q_0^2.
  • Sets 2a (p-set2atable.dat) and b (p-set2btable.dat) assume there is no charm distribution at Q_0^2, but that it turns on at the mass threshold, which is m_c=1.3 GeV for set 2a, and m_c = Q_0 = \sqrt{1.4} GeV for set 2b.

For all sets 1E-5 < x < 1 and 1.4 GeV^2 < Q^2 < 10 000 GeV^2. Using x and Q^2 outside the limits gives distributions at the corresponding limit: xg(x < x_0,Q^2) returns the value xg(x=x_0,Q^2), etc.

File getintPDF.f contains the interpolation routine getintPDF and the necessary setup routine setintPDF. Please see comments in getintPDF.f for further details and usage.

File examplePDF.f is a simple example program which demonstrates the usage of the setup and the interpolation routines.

Download EHKQSsets.tar.gz, 3.03 Mb

Package is tarred and gzipped; unpacking is done by:
gunzip EHKQSsets.tar.gz
tar -xvf EHKQSsets.tar.gz