Precision studies of the post-CT18 LHC Drell-Yan data in the CTEQ-TEA global analysis

In this study, we examine closely the impact of the post-CT18 LHC Drell-Yan data on parton distribution functions (PDFs) in the general CTEQ-TEA global analysis framework. We compare the two main theoretical predictions, the MCFM fixed order calculations at next-to-next-to-leading order (NNLO) and the ResBos2 NNLO matched to qT resummation up to next-to-next-to-next-to-leading logarithmic (N3LL) level. We find that the overall inclusive cross sections agree well but the fiducial distributions can differ at a percent level. We mainly discuss the result of the ResBos2 resummation calculation which yields a smaller Monte Carlo uncertainty, and a better description to the post-CT18 LHC Drell-Yan data. We find that the majority of post-CT18 LHC Drell-Yan data are consistent with the ATLAS 7 TeV W, Z data, which were included in the CT18A, but not CT18, fit and increases the strange-quark distribution at the small x region. The noticeable exception is that the ATLAS and LHCb 8 TeV W data pull d(d̄) quark PDFs to the opposite direction with respect to the ATLAS 7 TeV W, Z data. The inclusion of these post-CT18 LHC Drell-Yan datasets in the CTEQ-TEA global analysis is to update the CT18 PDFs following similar trends as CT18Z PDFs. The parton luminosities and a few phenomenological implications with the fiducial W^±,Z and inclusive H,tt̄,tt̄H productions at the 14 TeV LHC, as examples, are presented.