SciPost Phys. Proc. 8, 101 (2022) ·
published 13 July 2022
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There have been recent updates to the three global PDF fits (CT, MSHT and NNPDF), all
adding large amounts of data from the LHC, and this has resulted in significant changes
to the global PDFs. Given the impact that the new PDFs will have on physics comparisons
at the LHC, it is crucial to perform a benchmarking among the PDFs, similar in spirit to
that which was carried out for PDF4LHC15, widely used for LHC physics. In this article
we detail a benchmarking comparison of three global PDF sets - CT18, MSHT20 and
NNPDF3.1 - and their similarities and differences that have been observed. The end
result of this study will be a new PDF4LHC21 ensemble of combined PDFs suitable for a
wide range of LHC applications.
R.S. Thorne, S. Bailey, T. Cridge, L. Harland-Lang, A.D. Martin
SciPost Phys. Proc. 8, 018 (2022) ·
published 11 July 2022
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We present the new MSHT20 set of parton distribution functions (PDFs) of the
proton, determined from a global analysis of the available hard scattering
data and superseding the MMHT14 sets. The parameterisation is now adapted and
extended and we include a large number of new data sets:
the final HERA and Tevatron data, and a significant number of LHC data
sets on vector boson production, inclusive jets and top quark distributions.
We include up to NNLO QCD corrections for all data sets that play a major
role in the fit. There are some changes to central PDF values and a
significant reduction in the uncertainties, but the PDFs and the
predictions using them are generally within one standard deviation of the
MMHT14 results. We discuss the phenomenological impact of our results.