Parameter Samples and LHAPDF files for "Determination of proton PDF uncertainties with Markov chain Monte Carlo"

This Resource contains the parameter samples and LHAPDF files generated in the Publication https://doi.org/10.1103/5y5y-5yhy. Parameter samples The parameter samples are given in the file `ordered_parameter_samples.csv` and are in ascending order w.r.t. their $\chi^2$ value. The parameter values define the PDFs through the parameterization given in Sec. III.D in the paper. Note that the fixed parameter values are given in Table II. LHAPDF Files The Folder `MCMCproton.tar.gz` contains the LHAPDF files corresponding to the parameter samples in the `csv`-file. To extract, use `tar -xzf MCMCproton.tar.gz`. The scripts `plot_Fig_8_lhapdf.py` and `plot_Fig_8_neopdf` reproduces Fig. 8 in the paper relying on the `LHAPDF` and `NEOPDF` package respectively. As LHAPDF currently does not support MCMC samples as a valid format, we invented a custom format. The order of the PDF members is given as follows: Mem 0: Not The Central PDF. - This is the PDF that is defined through the average over the parameters: $PDF(\langle\{p_k\}\rangle)$. This is never used in the Paper and only there for reference. - Note $PDF(\langle\{p_k\}\rangle) \neq \langle PDF(\{p_k\})\rangle$ Mem 1-4068: The PDF samples in ascending order w.r.t. their $\chi^2$ value. - This is the same ordering as in the `.csv` file. - Mem 1: This is the PDF from the set of parameters with the best $\chi^2$ observed and used as the best fit value for the Cumulative $\chi^2$ method. - Mem 4068: This is the PDF from the set of parameters with the worst $\chi^2$ recorded.