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1. SMEFT chromomagnetic dipole operator contributions to $$t{{\bar{t}}}$$ production at approximate NNLO in QCD

   https://doi.org/10.1140/epjc/s10052-024-12938-9  

   Kidonakis, Nikolaos; Tonero, Alberto (June 2024, The European Physical Journal C)

   Abstract We study higher-order QCD corrections for the production of a top–antitop quark pair ($$t{{\bar{t}}}$$ $t\overline{t}$production) at the Large Hadron Collider in the Standard Model Effective Field Theory. We consider effects of new physics parametrized by the top-quark chromomagnetic dipole operator. We calculate new physics contributions to the total cross section at approximate NNLO, with second-order soft-gluon corrections added to the complete NLO result, including uncertainties from scale dependence and from parton distributions. We also calculate new physics contributions at approximate NNLO for differential distributions in top-quark transverse momentum. 

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2. 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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3. Total and Differential Cross Sections for Higgs and Top-Quark Production

   https://doi.org/10.3390/universe4110121  

   Kidonakis, Nikolaos (November 2018, Universe)

   I present theoretical calculations for Higgs-boson and top-quark production, including high-order soft-gluon corrections. I discuss charged-Higgs production in association with a top quark or a W boson, as well as single-top and top-antitop production. Total cross sections as well as transverse-momentum and rapidity distributions of the top quark or the Higgs boson are presented for various LHC energies. 

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4. Measurement of the inclusive and differential t$$ \overline{t} $$γ cross sections in the dilepton channel and effective field theory interpretation in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV

   https://doi.org/10.1007/JHEP05(2022)091  

   Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Damanakis, K.; Dragicevic, M.; Escalante Del Valle, A.; Frühwirth, R.; Jeitler, M.; et al (May 2022, Journal of High Energy Physics)

   A bstract The production cross section of a top quark pair in association with a photon is measured in proton-proton collisions in the decay channel with two oppositely charged leptons ( e ± μ ∓ , e + e − , or μ + μ − ). The measurement is performed using 138 fb − 1 of proton-proton collision data recorded by the CMS experiment at $$ \sqrt{s} $$ s = 13 TeV during the 2016–2018 data-taking period of the CERN LHC. A fiducial phase space is defined such that photons radiated by initial-state particles, top quarks, or any of their decay products are included. An inclusive cross section of 175 . 2 ± 2 . 5(stat) ± 6 . 3(syst) fb is measured in a signal region with at least one jet coming from the hadronization of a bottom quark and exactly one photon with transverse momentum above 20 GeV. Differential cross sections are measured as functions of several kinematic observables of the photon, leptons, and jets, and compared to standard model predictions. The measurements are also interpreted in the standard model effective field theory framework, and limits are found on the relevant Wilson coefficients from these results alone and in combination with a previous CMS measurement of the t $$ \overline{t} $$ t ¯ γ production process using the lepton+jets final state. 

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5. N3LO soft-gluon corrections in single-particle-inclusive kinematics and H+H− production

   https://doi.org/10.1007/JHEP06(2024)138  

   Kidonakis, Nikolaos; Tonero, Alberto (June 2024, Journal of High Energy Physics)

   A<sc>bstract</sc> We calculate the complete soft-gluon corrections for the production of colorless final states through N³LO in single-particle-inclusive kinematics. We present explicit analytical results and use them to study higher-order QCD corrections for the production of a heavy charged Higgs pair (H⁺H⁻) via quark-antiquark annihilation in the Two-Higgs-Doublet Model at LHC energies. We calculate the NNLO soft-gluon and virtual QCD corrections as well as the N³LO soft-gluon corrections to the total cross section and the charged-Higgs rapidity distribution. This is the first calculation of complete N³LO soft-gluon corrections for a process in single-particle-inclusive kinematics, and the results can be applied to other processes with colorless final states. 

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