arXiv subjects

Nikolaos Kidonakis

Publications and source records attributed to Nikolaos Kidonakis.

At least 73 records · Page 4Linked to original sources

arXiv2016

Theoretical results for top-quark cross sections and distributions

I present new results and updates for total cross sections and differential distributions in top-antitop pair and single-top production. Soft-gluon corrections are added to exact fixed-order results to provide the best predictions at approximate N$^3$LO for $t{\bar t}$ production and approximate NNLO for single-top production. Total cross sections and top-quark transverse-momentum and rapidity distributions are presented and compared with data at LHC and Tevatron energies. The cusp anomalous dimension at three and higher loops is also discussed.

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arXiv2016

High-precision theory for top-quark production

I present high-precision results for top quark production at hadron collider energies. Total and differential cross sections are calculated through aN$^3$LO for top-antitop pair production and through aNNLO for single-top production. Top production in association with a charged Higgs boson and via anomalous couplings is also briefly discussed.

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arXiv2016

Charged Higgs production in association with a top quark at approximate NNLO

I present approximate next-to-next-to-leading-order (aNNLO) total and differential cross sections for charged Higgs production in association with a top quark at LHC energies. The aNNLO results for the process $bg \rightarrow tH^-$ are derived from next-to-next-to-leading-logarithm (NNLL) resummation of soft-gluon corrections. Scale and parton-distribution uncertainties for the cross sections are shown. The top-quark transverse-momentum and rapidity distributions are also calculated.

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arXiv2016

Single-top transverse-momentum distributions at approximate NNLO

I present approximate next-to-next-to-leading-order (aNNLO) transverse-momentum ($p_T$) distributions in single-top production processes. The aNNLO results are derived from next-to-next-to-leading-logarithm (NNLL) resummation of soft-gluon corrections in the differential cross section. Single-top as well as single-antitop $p_T$ distributions are shown in $t$-channel, $s$-channel, and $tW$ production for LHC energies.

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arXiv2016

Three-loop cusp anomalous dimension and a conjecture for $n$ loops

I present analytical expressions for the cusp anomalous dimension in QCD through three loops in terms of elementary functions and ordinary polylogarithms. I observe interesting relations between the results at different loops and provide a conjecture for the $n$-loop cusp anomalous dimension in terms of the lower-loop results. I also present numerical results and simple approximate formulas for the cusp anomalous dimension relevant to top-quark production.

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arXiv2015

High-order threshold corrections for top-pair and single-top production

I present results for high-order corrections from threshold resummation to cross sections and differential distributions in top-antitop pair production and in single-top production. I show aN$^3$LO results for the total $t{\bar t}$ cross section as well as for the top-quark transverse momentum ($p_T$) and rapidity distributions, and the top-quark forward-backward asymmetry in $t{\bar t}$ production. I compare with the most recent Tevatron and LHC data, including at 13 TeV. I also present aNNLO results for cross sections and $p_T$ distributions in $t$-channel, $s$-channel, and $tW$-channel single-top production.

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arXiv2015

N$^3$LO calculations for top-quark differential cross sections near partonic threshold

I present calculations of approximate corrections from NNLL soft-gluon resummation for total and differential cross sections in top-antitop pair production and single-top production in hadronic collisions. I show that soft-gluon corrections from partonic threshold are the dominant contribution to top-quark production and closely approximate exact results. I present aN$^3$LO results for the total $t{\bar t}$ cross section, the top-quark $p_T$ and rapidity distributions, and the top-quark forward-backward asymmetry. I also provide updates for single-top production in the $t$, $s$, and $tW$ channels. Finally, I discuss top-quark production via anomalous gluon couplings.

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arXiv2015

N$^3$LO approximate results for top-quark differential cross sections and forward-backward asymmetry

I present a calculation of approximate N$^3$LO corrections from NNLL soft-gluon resummation for differential distributions in top-antitop pair production in hadronic collisions. Soft-gluon corrections are the dominant contribution to top-quark production and closely approximate exact results through NNLO. I show aN$^3$LO results for the total $t{\bar t}$ cross section, the top-quark $p_T$ and rapidity distributions, and the top-quark forward-backward asymmetry. The higher-order corrections are significant and they reduce theoretical uncertainties.

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arXiv2015

Theoretical results for electroweak-boson and single-top production

I present results from recent high-order calculations for the production of electroweak bosons and top quarks. In particular, I discuss $W$ and $Z$ boson production at large transverse momentum, single-top production, and FCNC top production. Theoretical predictions which include higher-order soft-gluon corrections are presented for total cross sections and differential distributions at the LHC.

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arXiv2015

The top quark forward-backward asymmetry at approximate N$^3$LO

I calculate the top quark forward-backward asymmetry at the Tevatron in both the laboratory frame and the $t{\bar t}$ rest frame. I show that soft-gluon corrections are the dominant contribution to the asymmetry and closely approximate exact results through next-to-next-to-leading order (NNLO). I present a calculation of the asymmetry including approximate next-to-next-to-next-to-leading-order (N$^3$LO) soft-gluon contributions from next-to-next-to-leading-logarithm (NNLL) resummation as well as electroweak corrections. Thus approximate N$^3$LO (aN$^3$LO) results are obtained, which significantly enhance and improve previous NNLO results. The theoretical aN$^3$LO result for the top quark forward-backward asymmetry at the Tevatron in the laboratory frame is ($6.8 \pm 0.3$)\%, and in the $t{\bar t}$ rest frame it is ($10.0 \pm 0.6$)\% which is in excellent agreement with recent Tevatron data.

hep-ph↗

arXiv2015

NNNLO soft-gluon corrections for the top-quark $p_T$ and rapidity distributions

I present a calculation of next-to-next-to-next-to-leading-order (NNNLO) soft-gluon corrections for differential distributions in top-antitop pair production in hadronic collisions. Approximate NNNLO (aNNNLO) results are obtained from soft-gluon resummation. Theoretical predictions are shown for the top-quark aNNNLO transverse momentum ($p_T$) and rapidity distributions at LHC and Tevatron energies. The aNNNLO corrections enhance previous results for the distributions but have smaller theoretical uncertainties.

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arXiv2014

Soft-Gluon Corrections in FCNC Top-Quark Production via Anomalous Gluon Couplings

We present a calculation of soft-gluon corrections in FCNC top-quark production via anomalous $t$-$q$-$g$ couplings. The soft anomalous dimension matrix is explicitly calculated at one-loop accuracy. This calculation allows threshold resummation at next-to-leading-logarithm accuracy. We also derive expressions for the soft-gluon corrections at NLO and at NNLO.

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arXiv2014

NNNLO soft-gluon corrections for the top-antitop pair production cross section

I present a calculation of next-to-next-to-next-to-leading-order (NNNLO) soft-gluon corrections for top-antitop pair production in hadronic collisions. Approximate NNNLO (aNNNLO) results are obtained by adding the NNNLO soft-gluon corrections to the complete next-to-next-to-leading-order (NNLO) cross section. Theoretical predictions are shown for the total aNNNLO $t{\bar t}$ cross section at LHC and Tevatron energies. The aNNNLO cross sections are larger but have smaller theoretical uncertainties than at NNLO.

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arXiv2014

NNLO soft-gluon corrections for the Z-boson and W-boson transverse momentum distributions

We present results for the $Z$-boson and $W$-boson transverse momentum ($p_T$) distributions for large $p_T$ at LHC and Tevatron energies. We calculate complete next-to-leading-order (NLO) QCD corrections as well as soft-gluon corrections at next-to-next-to-leading-order (NNLO) to the differential cross section. The NNLO soft-gluon contributions are derived from next-to-next-to-leading-logarithm (NNLL) resummation at two loops. We find enhancements of the $p_T$ distributions and reductions of the scale dependence when the NNLO corrections are included.

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arXiv2013

Top Quark Production

I discuss top quark production in hadronic collisions. I present the soft-gluon resummation formalism and its derivation from factorization and renormalization-group evolution, and two-loop calculations of soft anomalous dimensions in the eikonal approximation. I discuss the contributions of next-to-next-to-leading order (NNLO) soft-gluon corrections to the total cross sections and top-quark transverse momentum and rapidity distributions for top-antitop pair production, and for single-top production in the $t$ and $s$ channels and in association with a $W$ boson or a charged Higgs boson.

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arXiv2013

FCNC Top Quark Production via Anomalous Couplings

We calculate flavor-changing neutral current (FCNC) processes with top-quark production via anomalous couplings at LHC energies. We report on progress on the FCNC processes gu -> tZ, gu -> t gamma and gu -> tg. We go beyond leading order and include soft-gluon corrections through next-to-next-to-leading order.

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arXiv2013

Top quark transverse momentum and rapidity distributions

I present NNLO approximate calculations, based on NNLL resummation, for top quark differential transverse momentum and rapidity distributions. In particular recent results are presented for top-pair production and single-top production processes and compared to the latest experimental data from the LHC.

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arXiv2013

Differential cross sections for top-pair and single-top production

I present higher-order results, based on NNLL resummation, for differential transverse momentum and rapidity distributions in processes involving top quarks. In particular results are presented for top-pair production and for single-top production in different channels.

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