Parton distribution functions in nuclei
3rd version (2007)
Determination of nuclear parton distribution functions
and their uncertainties at next-to-leading order
M. Hirai, S. Kumano, T.-H. Nagai,
Phys. Rev. C76 (2007) 065207
(arXiv:0709.3038)
(1) [2009-12-22] If you run the code by the g95 compiler,
wrong outputs are obtained although there is no problem by the g77, gfortran, and
intel fortran.
- In the supplied subroutine (npdf07e.f),
the the array PDFG should be saved.
- Solution: Please use
"SAVE IREAD, BXG, CXG, DXG, PDFG"
in line 97 of npdf07e.f.
-
(Thank Dr. Stefano Melis for pointing out this issue.)
(2) [2007-12-12]
If you run the 2007 code for LO and NLO simultaneously
in the same nucleus,
- it could lead to wrong distributions.
- The supplied LO or NLO grid files are called once in the beginning of the program
(npdf07e.f).
- So, if you run the code, for example, for NLO without changing the nucleus
after running it for LO,
- the LO grid data are still used and the code produces
wrong distributions for NLO.
-
Solution: Please run the code for LO and NLO independently.
For getting the 2007 version (note: ed=1 version)
of our nuclear parton distributions
(npdf07-v1_1.tar.gz: The above bug (1) is fixed.),
please
click
here.
The ed=free version could be obtained upon email request.
The file npdf07-v1_1.tar.gz contains the following files.
-
npdf07e.f: FORTRAN subroutine source file.
For uncertainty studies by the Hessian method,
the inverse matrix of Hessian (error matrix)
can be used by declaring a common block: COMMON/ERRM/EM(12,12).
-
sample_npdf07e.f: Grid-data-table file for NLO set of the gradient terms in Ca
-
EM.inc: Include file called in npdf07e.f. It indiates the error matrix.
- ...
-
npdfCa_LO.grd: Grid-data-table file for LO set of the PDFs in Ca
-
gradCa_LO.grd: Grid-data-table file for LO set of the gradient terms in Ca
-
npdfCa_NLO.grd: Grid-data-table file for NLO set of the PDFs in Ca
-
gradCa_NLO.grd: Grid-data-table file for NLO set of the gradient terms in Ca
- ...
- Grid files for other nuclei
- ...
2nd version (2004)
Nuclear parton distribution functions and their uncertainties,
M. Hirai, S. Kumano, T.-H. Nagai,
Phys. Rev. C70 (2004) 044905
(hep-ph/0404093).
For getting the 2004 version of our nuclear parton distributions
(npdf04.tar.gz),
please
click
here.
1st version (2001)
For getting the 2001 version of our nuclear parton distributions
(saga01.tar.gz),
please
click
here.
From the enclosed FORTRAN program, one can obtain nuclear parton
distribution functions
(xuv, xdv, xqbar, xg) for a specified nucleus at a given x and Q^2 point
within the range,
10^(-9)<=x<=1, 1<=Q^2<10^5 GeV^2. See the enclosed "Readme" file and
the Appendix section
of the Phys. Rev. D paper for the details.