Presentation of paper on HERAPDF2.0NNLOJet fit — 11/Aug/2020
After presentation of the analysis from the authors, the following comments and questions were received:
- Thomas Gehrmann informed all that there is a bug in the NNLO predictions which seems to most strongly affect the DIS predictions:
-> the issue with the DIS predictions was only found over the weekend.
-> it is not clear why predictions for DIS are affected and pp collisions not.
-> the bug looks to affect low values of \mu most strongly.
-> this may result in some numerical changes in the results and use of low Q^2/\mu data.
-> work is ongoing as high priority.
o Those present agreed to continue with the editorial process as originally planned and update the analysis as and when new grids become available.
- Stefan Schmitt asked if other PDF sets would be released beyond HERAPDF2.0NNLOJet ? The authors are proposing to just release the new NNLO set when including jets in the fits.
- Stefan Schmitt asked about comparing the uncertainties (on p.30 of the talk) using the same alpha_s. This will be plotted and discussed at the editorial board meeting.