arXiv subjects

Nikolaos Kidonakis

Publications and source records attributed to Nikolaos Kidonakis.

At least 37 records · Page 2Linked to original sources

arXiv2023

Top-quark cross sections and distributions at aN$^3$LO

We present theoretical predictions for top-quark total cross sections and for differential distributions in top-quark transverse momentum and rapidity. Third-order soft gluon corrections are added to the complete NNLO quantities to provide approximate N$^3$LO (aN$^3$LO) results, and electroweak corrections at NLO are also included. We calculate the theoretical uncertainties from scale dependence and from parton distribution functions in the proton, and estimate their impact on the total and differential cross sections. The higher-order corrections are large and they reduce the scale uncertainties. The results presented in this work include the best current theoretical input and are in good agreement with recent data from the LHC.

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arXiv2023

aNNLO results for $t{\bar t}γ$ cross sections

We present theoretical calculations of total cross sections and top-quark transverse-momentum and rapidity distributions in the associated production of a top-antitop pair with a photon ($t{\bar t}γ$ production). We include complete QCD and electroweak corrections at NLO as well as soft-gluon corrections at approximate NNLO (aNNLO). The aNNLO corrections are very significant, they decrease theoretical uncertainties, and they are needed for better comparison with data from the LHC.

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arXiv2023

Higher-order corrections for $tqZ$ production

We present theoretical results for the associated production of a single top quark and a $Z$ boson ($tqZ$ production) at LHC energies. We calculate higher-order corrections from soft-gluon emission for this process. We compute the approximate NNLO (aNNLO) cross section at LHC energies, including uncertainties from scale dependence and from parton distributions. We also calculate the top-quark rapidity distribution. The aNNLO corrections are significant and enhance the NLO cross section, and their inclusion provides a more precise theoretical prediction.

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arXiv2023

Four-loop massive cusp anomalous dimension in QCD: a calculation from asymptotics

I present a general method for determining the massive cusp anomalous dimension in QCD to a very high degree of accuracy using its asymptotic behavior at small and large quark velocities. I show that the method works exceedingly well at two and three loops where exact results are already known. I then present a calculation of the massive cusp anomalous dimension using its asymptotics at four loops, and I provide a detailed study of the results for different values of the number of flavors and for separate color structures. The method can be further extended and applied to higher numbers of loops.

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arXiv2022

Higher-order corrections in $t{\bar t}γ$ cross sections

We study higher-order QCD corrections for the associated production of a top-antitop quark pair and a photon ($t{\bar t}γ$ production) in proton-proton collisions. We calculate the approximate NNLO cross section, with second-order soft-gluon corrections added to the complete NLO result, including uncertainties from scale dependence and from parton distributions. We compare our results to recent measurements from the LHC, and find that the soft-gluon corrections provide improved agreement with the data. We also calculate differential distributions in top-quark transverse momentum and rapidity.

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arXiv2022

Report of the Topical Group on Top quark physics and heavy flavor production for Snowmass 2021

This report summarizes the work of the Energy Frontier Topical Group on EW Physics: Heavy flavor and top quark physics (EF03) of the 2021 Community Summer Study (Snowmass). It aims to highlight the physics potential of top-quark studies and heavy-flavor production processes (bottom and charm) at the HL-LHC and possible future hadron and lepton colliders and running scenarios.

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arXiv2022

Soft-gluon corrections for $tqZ$ production

We study soft-gluon corrections for the associated production of a single top quark and a $Z$ boson ($tqZ$ production) at hadron colliders. We find that the radiative corrections are dominated by soft-gluon emission. We calculate the approximate NNLO (aNNLO) cross section at LHC energies, including uncertainties from scale dependence and from parton distributions. We also calculate differential distributions in top-quark rapidity. We show that the aNNLO corrections are significant and they enhance the NLO cross section while decreasing theoretical uncertainties.

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arXiv2022

QCD corrections in $tqγ$ production at hadron colliders

We study QCD corrections for the associated production of a single top quark and a photon ($tqγ$ production) at hadron colliders. We calculate the NLO cross section at LHC and future collider energies for a variety of kinematical cuts, and we estimate uncertainties from scale dependence and from parton distributions. We also calculate differential distributions in top-quark transverse-momentum and rapidity as well as photon energy. Finally, we study higher-order corrections from soft-gluon emission for this process, and we provide approximate NNLO (aNNLO) results for the cross section and top-quark differential distributions. We also compare our calculations with recent measurements from CMS and ATLAS at the LHC and find that the aNNLO corrections improve the comparison between the data and the Standard Model predictions.

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arXiv2022

Higher-order corrections for $t{\bar t}$ production at high energies

I present theoretical calculations of $t{\bar t}$ production cross sections through aN$^3$LO in proton-proton collisions. I show that soft-gluon corrections dominate the perturbative expansion not only for LHC energies but also for future collider energies through 100 TeV. Detailed results are presented for various collision energies. The $K$-factors are large and increase slowly with increasing energy. The scale uncertainties decrease greatly as we move to higher perturbative orders.

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arXiv2021

Top-quark production at approximate N$^3$LO

I discuss recent theoretical results with soft-gluon corrections for various top-quark production processes through approximate N$^3$LO, including soft anomalous dimensions through three loops. I present numerical results for total cross sections and differential distributions for top-pair and $tW$ production as well as for three-particle final states with a top quark and a Higgs boson. I show that soft-gluon corrections are dominant for a large range of collider energies.

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arXiv2021

Three-loop soft anomalous dimensions in QCD

I present results for soft anomalous dimensions through three loops for many QCD processes. In particular, I give detailed expressions for soft anomalous dimensions in various processes with electroweak and Higgs bosons as well as single top quarks and top-antitop pairs.

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arXiv2021

Soft-gluon corrections for the associated production of a single top quark and a Higgs boson

We discuss soft-gluon resummation for the associated production of a single top quark and a Higgs boson ($tqH$ production) in single-particle-inclusive (1PI) kinematics. We present analytical results for the higher-order corrections and numerical results for the cross sections at LHC energies. We calculate approximate NNLO total rates, including scale dependence and uncertainties from parton distributions, as well as top-quark transverse-momentum and rapidity distributions. In all cases we find that the soft-gluon corrections are dominant and provide important contributions to the total and differential cross sections.

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arXiv2021

Resummation for $tqH$ production

We present results with soft-gluon resummation for the associated production of a single top quark and a Higgs boson. We present analytical results for the higher-order soft-gluon corrections and numerical results for the total cross section and top-quark transverse momentum and rapidity distributions at LHC energies.

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arXiv2021

$tW$ and $tZ'$ production at hadron colliders

We present theoretical results with soft-gluon corrections for two separate processes: (1) the production of a single top quark in association with a $W$ boson in the Standard Model; and (2) the production of a single top quark in association with a heavy $Z'$ boson in new physics models with or without anomalous couplings. We show that the higher-order corrections from soft-gluon emission are dominant for a wide range of collider energies. Results are shown for the total cross sections and top-quark transverse-momentum and rapidity distributions for $tW$ and $tZ'$ production at LHC and future collider energies up to 100 TeV. The uncertainties from scale dependence and parton distribution functions are also analyzed.

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arXiv2021

Three-loop soft anomalous dimensions for top-quark processes

I present results for soft anomalous dimensions through three loops for several processes involving the production of top quarks. In particular, I discuss single-top and top-pair production. I also present some numerical results for double-differential distributions in $t{\bar t}$ production through approximate N$^3$LO.

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arXiv2021

Higher-order corrections for $tW$ production at high-energy hadron colliders

We discuss cross sections for $tW$ production in proton-proton collisions at the LHC and at higher-energy colliders with energies of up to 100 TeV. We find that, remarkably, the soft-gluon corrections are numerically dominant even at very high collider energies. We present results with soft-gluon corrections at approximate NNLO and approximate N$^3$LO matched to complete NLO results. These higher-order corrections are large and need to be included for better theoretical accuracy and smaller scale dependence. Total cross sections as well as top-quark and $W$-boson transverse-momentum and rapidity distributions are presented using various recent sets of parton distribution functions.

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arXiv2020

Soft anomalous dimensions and resummation in QCD

I discuss and review soft anomalous dimensions in QCD that describe soft-gluon threshold resummation for a wide range of hard-scattering processes. The factorization properties of the cross section in moment space and renormalization-group evolution are implemented to derive a general form for differential resummed cross sections. Detailed expressions are given for the soft anomalous dimensions at one, two, and three loops, including some new results, for a large number of partonic processes involving top quarks, electroweak bosons, Higgs bosons, and other particles in the Standard Model and beyond.

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arXiv2020

Resummation for $2\rightarrow n$ processes in single-particle-inclusive kinematics

We present a formalism and detailed analytical results for soft-gluon resummation for $2\rightarrow n$ processes in single-particle-inclusive (1PI) kinematics. This generalizes previous work on resummation for $2 \rightarrow 2$ processes in 1PI kinematics. We also present soft anomalous dimensions at one and two loops for certain $2 \rightarrow 3$ processes involving top quarks and Higgs or $Z$ bosons, and we provide some brief numerical results.

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