mc variations
This PR contains the definition of three additional theories with different values of the charm mass:
- mc = 1.4 GeV for the PDF4LHC21 combination;
- mc = 1.38 and mc=1.64 for the charm paper. The theories are available from the server. Fits are available at:
- https://www.wiki.ed.ac.uk/display/nnpdfwiki/List+of+fits+and+benchmarks (for the PDF4LHC21 combination)
- https://www.wiki.ed.ac.uk/display/nnpdfwiki/NNPDF4.0+fits+for+charm+paper (for the charm paper)