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1. NNLO constraints on proton PDFs from the SeaQuest and STAR experiments and other developments in the CTEQ-TEA global analysis

   https://doi.org/10.21468/SciPostPhysProc.8.005  

   Guzzi, Marco ; Hobbs, Timothy ; Hou, Tie-Jiun ; Jing, Xiaoxian ; Xie, Keping ; Courtoy, Aurore ; Dulat, Sayipjamal ; Gao, Jun ; Huston, Joey ; Nadolsky, Pavel ; et al ( January 2022 , SciPost Physics Proceedings)

   We review progress in the global QCD analysis by the CTEQ-TEA group since the publication of CT18 parton distribution functions (PDFs) in the proton. Specifically, we discuss comparisons of CT18 NNLO predictions with the LHC 13 TeV measurements as well as with the FNAL SeaQuest and BNL STAR data on lepton pair production. The specialized CT18X PDFs approximating saturation effects are compared with the CT18sx PDFs obtained using NLL/NLO small-$x$ resummation. Short summaries are presented for the special CT18 parton distributions with fitted charm and with lattice QCD inputs. A recent comparative analysis of the impact of deuteron nuclear effects on the parton distributions by the CTEQ-JLab and CTEQ-TEA groups is summarized. 

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2. Heavy-flavor impact on CTEQ-TEA global QCD analyses

   https://doi.org/10.1051/epjconf/202227000004  

   Guzzi, Marco ; Ablat, Alim ; Dulat, Sayipjamal ; Hou, Tie-Jiun ; Nadolsky, Pavel ; Sitiwaldi, Ibrahim ; Xie, Keping ; Yuan, C.-P. ( January 2022 , EPJ Web of Conferences)

   Bruno, G.E. ; Chiodini, G. ; Colangelo, P. ; Corianò, C. ; Creanza, D.M. ; De Fazio, F. ; Nappi, E. (Ed.)

   We discuss heavy-flavor production at hadron colliders in recent global QCD analyses to determine parton distribution functions (PDFs) in the proton. We discuss heavy-flavor treatments in precision theory predictions at the LHC. In particular, we discuss factorization schemes in presence of heavy flavors in proton-proton collisions, as well as the impact of heavy-flavor production at the LHC on PDFs. We show results of recent updates beyond CT18, the latest global QCD analysis from the CTEQ-TEA group. 

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3. LHC and DIS experimental datain the CT18(Z) global QCD analysis

   https://doi.org/10.22323/1.352.0021  

   Nadolsky, Pavel ; Hou, Tie-Jiun ; Xie, Keping ; Gao, Jun ; Dulat, Sayipjamal ; Guzzi, Marco ; Huston, Joey Walter ; Hobbs, Timothy J. ; Pumplin, Jon ; Schmidt, Carl ; et al ( August 2019 , Proceedings of science)

   We discuss implementation of the LHC experimental data sets in the new CT18 global analysis of quantum chromodynamics (QCD) at the next-to-next-leading order of the QCD coupling strength. New methodological developments in the fitting methodology are discussed. Behavior of the CT18 NNLO PDFs for the conventional and "saturation-inspired" factorization scales in deep-inelastic scattering is reviewed. Four new families of (N)NLO CTEQ-TEA PDFs are presented: CT18, A, X, and Z. 

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4. LHC and DIS experimental data in the CT18(Z) global QCD analysis

   https://doi.org/doi.org/10.22323/1.352.0021  

   P. Nadolsky, T.J. Hou ( October 2019 , XXVII International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2019) - Working Group 1: Structure Function and Parton Densiies)

   null (Ed.)

   We discuss implementation of the LHC experimental data sets in the new CT18 global analysis of quantum chromodynamics (QCD) at the next-to-next-leading order of the QCD coupling strength. New methodological developments in the fitting methodology are discussed. Behavior of the CT18 NNLO PDFs for the conventional and "saturation-inspired" factorization scales in deep-inelastic scattering is reviewed. Four new families of (N)NLO CTEQ-TEA PDFs are presented: CT18, A, X, and Z 

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5. The PDF4LHC21 combination of global PDF fits for the LHC Run III*

   https://doi.org/10.1088/1361-6471/ac7216  

   Ball, Richard D ; Butterworth, Jon ; Cooper-Sarkar, Amanda M ; Courtoy, Aurore ; Cridge, Thomas ; De Roeck, Albert ; Feltesse, Joel ; Forte, Stefano ; Giuli, Francesco ; Gwenlan, Claire ; et al ( July 2022 , Journal of Physics G: Nuclear and Particle Physics)

   Abstract A precise knowledge of the quark and gluon structure of the proton, encoded by the parton distribution functions (PDFs), is of paramount importance for the interpretation of high-energy processes at present and future lepton–hadron and hadron–hadron colliders. Motivated by recent progress in the PDF determinations carried out by the CT, MSHT, and NNPDF groups, we present an updated combination of global PDF fits: PDF4LHC21. It is based on the Monte Carlo combination of the CT18, MSHT20, and NNPDF3.1 sets followed by either its Hessian reduction or its replica compression. Extensive benchmark studies are carried out in order to disentangle the origin of the differences between the three global PDF sets. In particular, dedicated fits based on almost identical theory settings and input datasets are performed by the three groups, highlighting the role played by the respective fitting methodologies. We compare the new PDF4LHC21 combination with its predecessor, PDF4LHC15, demonstrating their good overall consistency and a modest reduction of PDF uncertainties for key LHC processes such as electroweak gauge boson production and Higgs boson production in gluon fusion. We study the phenomenological implications of PDF4LHC21 for a representative selection of inclusive, fiducial, and differential cross sections at the LHC. The PDF4LHC21 combination is made available via the LHAPDF library and provides a robust, user-friendly, and efficient method to estimate the PDF uncertainties associated to theoretical calculations for the upcoming Run III of the LHC and beyond. 

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