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1. 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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2. 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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3. Progress in top-quark pair production cross section calculations and impact on parton distribution functions of the proton

   https://doi.org/10.22323/1.478.0332  

   Guzzi, Marco; Ablat, Alim; Dulat, Sayipjamal; Hou, T-J; Kidonakis, Nikolaos; Sitiwaldi, Ibrahim; Tonero, Alberto; Xie, Keping; Yuan, C-P (January 2025, Sissa Medialab)

   We discuss the impact of eligible top-quark pair production differential cross-section measurements at the LHC with a collision energy of 13 TeV on the parton distribution functions (PDFs) of the proton as well as the impact of approximate next-to-next-to-next-to-leading order (aN3LO) QCD corrections combined with next-to-leading order (NLO) electroweak (EW) corrections on tt¯ observables. We illustrate the effects on the gluon PDF at large x from an optimal baseline selection of data in NNLO global fits, and show comparisons between the theory prediction for tt¯ total and differential cross sections at aN3LO QCD combined with NLO EW and recent measurements from the ATLAS and CMS collaborations at the LHC. 

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4. 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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5. First simultaneous analysis of transverse momentum dependent and collinear parton distributions in the proton

   Barry, P; Prokudin, A; Anderson, T; Cocuzza, C; Gamberg, L; Melnitchouk, W; Moffat, E; Pitonyak, D; Qiu, J; Sato, N; et al (October 2025, arXiv.org)

   We present the first simultaneous global QCD analysis of unpolarized transverse momentum dependent (TMD) and collinear parton distribution functions (PDFs) in the proton. Our study incorporates data from deep-inelastic scattering, Drell-Yan, inclusive weak boson, W+charm, and jet production involving PDFs, as well as TMD Drell-Yan and Z-boson production data from fixed target and collider experiments sensitive to both TMD and collinear distributions. The analysis is performed at next-to-next-to-leading logarithmic accuracy for QCD resummation in TMD observables and next-to-leading order for observables described in collinear factorization. The combined analysis improves knowledge of both TMD and collinear PDFs, particularly in the sea-quark sector, providing a consistent simultaneous description of the aforementioned observables. 

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