相关论文: The reaction e+e- -> t tbar g at next-to-leading o…
The production of top quark pairs accompanied by a hard gluon in $e^+e^-$ annihilation is studied including next-to-leading order corrections in the strong coupling. At leading order, the fraction r of $t\bar{t}g$ events with respect to all…
We study the effects of QCD corrections to the process $e^+e^-\rightarrow t\bar t+X\rightarrow b\ell^+\nu \bar b\ell^-\bar \nu+X$ above threshold. We show how to treat consistently to ${\cal O}(\alpha_s)$ the gluon radiation in both the…
We calculate the linear polarization of gluons radiated off top quarks produced in e^+e^- annihilations. For typical top pair production energies at the Next-Linear-Collider (NLC) the degree of linear polarization remains close to its soft…
In this thesis we describe the calculation of the process e+ e- --> Z/gamma -> Q Qbar + X, where Q is a heavy quark, X is anything else at order alpha_s^2.
In this paper we describe the calculation of the process e+e- -> Z/gamma -> QQbar + X, where Q is a heavy quark, at order alpha_s^2.
I give an introduction to the effective field theory description of top pair production at threshold in e+e- annihilation. The impact of the summation of logarithms of the top quark velocity including most recent results at…
We analyze the four-fermion reactions e+e- -> 4f containing a single top quark and three other fermions, a possible decay product of the resonant anti-top quark, in the final state. This allows us to estimate the contribution of the…
We calculate the next-to-next-to-leading order correction to the cross section for top quark pair production in e+e- annihilation in the threshold region, resumming all O [ (alpha_s/beta)^n (alpha_s^2, beta^2, alpha_s beta) ] terms of…
We calculate the spin density matrix of top quark pairs for the reaction $e^+e^-\to t\bar{t}X$ to order $\alpha_s$. As an application we show next-to-leading order results for a variety of spin observables for the $t\bar{t}$ system. These…
We present the full O(alpha_s) longitudinal spin-spin correlations for heavy-quark pair production at e+ e- high-energy colliders in closed analytical form. In such reactions, quark and antiquark have strongly correlated spins, and the…
We report on a complete calculation of electroweak production of top quark pairs in $e^+e^-$ annihilation at next-to-next-to-leading order in Quantum Chromodynamics. Our setup is fully differential and can be used to calculate any…
The multiplicity of heavy quarks from gluon splitting in e+e- annihilation has now been theoretically calculated and experimentally measured at LEP. However, the experimental measurement requires theoretical input for the shape of the…
The cross-section for the production of $t\bar{t}$ pairs in $e^+e^-$-annihilation via a virtual photon is determined up to order $\alpha_s^2$. For the cm-energies of interest the effect of the top mass may not be considered as a small…
We determine the O(\alpha_s) radiative corrections to polarized top quark pair production in e+ e- -annihilations with a specified gluon energy cut. We write down fully analytical results for the unpolarized and polarized O(\alpha_s) cross…
We review the physics involved in the production and decay of top quarks in e^+e^- -> ttbar near threshold, with special emphasis on the recent theoretical study on the decay process of top quarks in the threshold region. The energy-angular…
Next-to-leading order calculations for heavy quark three-jet production in e+e- annihilation are reviewed. Their applications for the measurement of the b-quark mass at LEP/SLC and for the test of flavour independence of the strong coupling…
Top quark pair production close to threshold at a next linear collider is discussed, with special focus on the influence of rescattering corrections. Numerical results are shown for the differential cross-section, i.e. the momentum…
The most interesting Higgs-production processes at future e+ e- colliders belong to the process class e+ e- -> f anti-f H. We study the full O(alpha) corrections to this reaction in the Standard Model for neutrinos and top quarks in the…
Future hadron collider experiments are expected to record large to huge samples of $t\bar t$ events. The analysis of these data with respect to $t\bar t$ spin-spin correlations requires precise predictions of the production of these quark…
We present the third-order QCD prediction for the production of top-anti-top quark pairs in electron-positron collisions close to the threshold in the dominant S-wave state. We observe a significant reduction of the theoretical uncertainty…