Related papers: Top quark pair production near the threshold in e+…
One of the most challenging open problems in heavy quarkonium physics is the double charm production in $e^+e^-$ annihilation at B factories. The measured cross section of $e^+ e^- \to J/\psi + \eta_c$ is much larger than leading order (LO)…
The top-antitop energy asymmetry is a promising observable of the charge asymmetry in jet-associated top-quark pair production at the LHC. We present new predictions of the energy asymmetry in proton-proton collisions at 13 TeV, including…
We summarize the quantitative results of our analysis [1] of top-pair photoproduction in semileptonic mode in $pe$ collisions at the LHeC and FCC-he. We define three photoproduction regions, based on the rapidity acceptance range of the…
The cross section of top pair production in hadronic collisions to O(alpha \alpha_s^2) is calculated within the General 2-Higgs-Doublet Model and the Minimal Supersymmetric Standard Model. At the parton level the O(alpha) one-loop…
In this talk electroweak corrections related to the finite top quark lifetime to the total top pair threshold e+e- cross section at NNLL order are discussed. We include the absorptive parts in electroweak matching conditions of the NRQCD…
The electric dipole moment (EDM) of the top quark is calculated in a model with a vector like multiplet which mixes with the third generation in an extension of the MSSM. Such mixings allow for new CP violating phases. Including these new…
An optimal-observable analysis of the lepton angular and energy distributions from top-quark pair production with semi-leptonic decays in e+e- collisions is used to predict the potential sensitivity of the FCC-ee to the couplings of the top…
In this letter, we evaluate potential of linear $e^+e^-$ colliders to measure the top quark mass in radiative events and in a suitable short-distance scheme. We present a calculation of the differential cross section for production of a top…
We present calculations of higher-order QCD and electroweak (EW) corrections to the associated production of a top-antitop quark pair and a $Z$ boson, i.e. $t{\bar t}Z$ production, in proton collisions. We find that the contributions from…
We study QCD corrections for the associated production of a single top quark and a photon ($tq\gamma$ production) at hadron colliders. We calculate the NLO cross section at LHC and future collider energies for a variety of kinematical cuts,…
We suggest an infrared-insensitive quark mass, defined by subtracting the soft part of the quark self energy from the pole mass. We demonstrate the deep relation of this definition with the static quark-antiquark potential. At leading order…
The top-pair $t\bar t$ production cross section close to threshold in $e^+e^-$ collisions is strongly affected by the small lifetime of the top quark. Since the cross section is defined through final states containing the top decay…
We study the potential of future lepton colliders to probe violation of the CP symmetry in the top quark sector. In certain extensions of the Standard Model, such as the two-Higgs-doublet model (2HDM), sizeable anomalous top quark dipole…
We discuss in detail top quark polarization in above-threshold (t \bar t)-production at a polarized linear e^+ e^- collider. We pay particular attention to the minimization and maximization of the polarization of the top quark by tuning the…
We present a detailed investigation of the NLO polarization of the top quark in t t-bar production at a polarized linear e^+ e^- collider with longitudinally polarized beams. By appropiately tuning the polarization of the beams one can…
A measurement of observables sensitive to spin correlations in $t\bar{t}$ production is presented, using 36.1 fb$^{-1}$ of $pp$ collision data at $\sqrt{s} = 13$ TeV recorded with the ATLAS detector at the Large Hadron Collider.…
We study top quark pair production in association with a Z boson at the Large Hadron Collider (LHC) and investigate the prospects of measuring the couplings of top quarks to the Z boson. To date these couplings have not been constrained in…
Single and pair top-quark production in proton-lead (p-Pb) and lead-lead (Pb-Pb) collisions at the CERN Large Hadron Collider (LHC) and future circular collider (FCC) energies, are studied with next-to-leading-order perturbative QCD…
The measurement of the top quark pair production cross section in proton-antiproton collisions at 1.96 TeV is a test of quantum chromodynamics and could potentially be sensitive to new physics beyond the standard model. I report on the…
It is shown that if electron and positron beams at a linear collider are transversely polarized, azimuthal asymmetries of the final-state top quark in e+e- --> t tbar can be used to probe a combination of couplings of left and right…