Related papers: Analytic O(alpha_s) Results for Bottom and Top Qua…
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…
The talk is on a computational set-up for calculating the production of a massive quark-antiquark pair in electron positron collisions to order $\alpha_s^2$ in the coupling of quantum chromodynamics (QCD) at the differential level using the…
We examine the O(alpha_s) forward-backward asymmetries for the production process e+ e- --> gamma,Z --> q qbar (g), tagging the outgoing heavy-quark jet at center-of-momentum energies off the Z-peak. The complicated analytic results are…
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 use a recent O(alpha_s^2) calculation of the differential cross section for the production of heavy quarks in e+e- annihilation to compute a few moments of the heavy quark single-inclusive production cross section. We verify that,…
The cross section for bottom quark production is calculated for the HERA-B experiment. We consider both the order $\alpha_s^3$ cross section and the resummation of soft gluon corrections in all orders of QCD perturbation theory.
Using a Generic spin basis, we present a general formalism of one-loop radiative corrections to the spin correlations in the top quark pair production at the Next Linear Collider, and calculate the O(\alpha_s) QCD corrections under the soft…
The next-to-next-to-leading order (NNLO) QCD corrections to top quark threshold pair production in gamma-gamma collisions are computed. The NNLO effects turn out to be significant. Threshold cross sections in gamma-gamma and e+e- collisions…
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…
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,…
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 article we evaluate mass corrections up to $O((m^2/q^2)^6)$ to the three-loop polarization function induced by an axial-vector current. Special emphasis is put on the evaluation of the singlet diagram which is absent in the vector…
We have calculated the complete O(alpha) and O(alpha_s) radiative corrections to the Higgs-production process e+ e- -> t anti-t H in the Standard Model. This process is particularly interesting for the measurement of the top-quark Yukawa…
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.
Some of the most interesting Higgs-production processes at future e+ e- colliders are of the type e+ e- -> f anti-f H. We present a calculation of the complete O(alpha) corrections to these processes in the Standard Model for final-state…
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 discuss the resummation of the potentially large O((\beta_0\alpha_s)^n) QCD corrections to the total cross section of the process e^+e^- \to t \bar t near the threshold. In this approximation, the cross section factorization into the…
We evaluate the next-to-leading-order QCD corrections of O(alpha_s^2 G_F M_t^2) to the Standard-Model l^+l^-H, ZZH, and W^+W^-H couplings in the heavy-top- quark limit. Exploiting these results together with knowledge of Delta rho to the…
The exchange of gluons between heavy quarks produced in $e^+e^-$ interactions results in an enhancement of their production near threshold. We study QCD threshold effects in $\gamma\gamma$ collisions. The results are relevant to heavy quark…
We compute the 3-loop O(\alpha \alpha_s) correction to the Higgs boson production cross section arising from light quarks using an effective theory approach. Our calculation probes the factorization of QCD and electroweak perturbative…