xFitter is an open source QCD fit framework desinged to extract PDFs and assess the impact of new data. The xFitter project is is a common initiative by the H1 and ZEUS collaborations and extended to the LHC collaborations to provide precision QCD analyses. xFitter has been used as one of the main software packages for the determination of the HERA proton parton densities (PDFs), HERAPDFs. For further details and information, please check the xfitter web page.
The current package includes code to fit DIS inclusive cross section data, Drell-Yan, jet, ttbar and other processes (using APPLGRID and FastNLO interfaces).
Please refer to the INSTALLATION file.
The software behaviour is controlled by two files with steering commands.
steering.txt -- controls the main "stable" (un-modified during minimisation) parameters.
The file also contains
names of data files to be fitted to, definition
of kinematic cuts
parameters.yaml -- new unified parameter file, to control parameters transfered to the
reaction interfaces.
For documentation of the code, please use https://gitlab.cern.ch/fitters/xfitter/-/wikis/home
If the results obtained with the program are to be included in a scientific publication, add a reference to the xFitter paper together with the xFitter web portal: xfitter.org
"HERAFitter, Open Source QCD Fit Project" By S. Alekhin at al., DESY Report 14-188, 7 Nov 2014, Published in EPJC (2015), 75: 304, e-Print: arXiv:1410.4412 [hep-ex]
In addition to the main xFitter paper, additional references to be cited for specific modules and software packages can be found in the REFERENCES file.
xFitter is distributed under the GPL v3 license, see LICENCE for more details.