Related papers: Why e+ e- to T Tbar is Different
New heavy gauge bosons exist in many models of new physics beyond the standard model of particle physics. Discovery of these W^\prime and Z^\prime resonances and the establishment of their spins, couplings, and other quantum numbers would…
Recent measurements of top-quark production at hadron colliders are reviewed. The inclusive top-quark pair production is determined at four centre-of-mass energies at Tevatron and LHC with experimental uncertainties that are close to the…
Recent calculations are presented of top quark polarization in $t\bar t$ pair production close to threshold. S-P-wave interference gives contributions to all components of the top quark polarization vector. Rescattering of the decay…
The presented results on top quark properties include measurements of the top quark pair charge asymmetry, the top quark polarization in pair production and single top production, the W helicity in top quark decays. Results of spin…
The production of W+ W- b bbar from e+ e- collisions at energies close to the t tbar threshold is dominated by the resonant process with a nearly on-shell t tbar intermediate state. The W b pairs in the final state can also be reached…
The study of the top quark's properties is an important part of the LHC programme. In earlier work, we have studied the rare decay $t \to b \bar b c$, using effective operators to capture the effects of physics beyond the Standard Model.…
It was reported that the NNLO correction to the total cross section near the ttbar threshold in e+e- collisions is as large as the NLO correction to it. In the thesis, we improve the convergence of the perturbative series of the total cross…
In the framework of the nonrelativistic diquark model of the heavy baryons and the perturbative approach of QCD we predict the value and energy dependence for the total cross section of the Lambda_b- and Sigma_b^* -baryons pair production…
We report observation of the electroweak production of single top quarks in ppbar collisions at sqrt(s) = 1.96 TeV based on 2.3 fb^-1 of data collected by the D0 detector at the Fermilab Tevatron Collider. Using events containing an…
We compare the impact of top-quark spin polarization effects in Higgs boson production in association with top-quark pairs and in corresponding backgrounds at the LHC. Because of the spin-zero nature of the Higgs boson, one expects, in the…
This paper studies the electroweak production of all possible four-fermion states in $e^+e^-$ collisions with non-standard triple gauge boson couplings. All $CP$ conserving couplings are considered. It is an extension of the methods and…
At very high energies, pair production ($\gamma\to e^+e^-$) exhibits many interesting features. The momentum transfer from the target is very small, so the reaction probes the macroscopic properties of the target, rather than individual…
We discuss the possibility and likelihood that one may observe {\it like sign} top quark pair production at the Linear Collider. In general two Higgs models, flavor changing couplings involving top quark could be quite sizable. Exotic…
Topological interactions will be generated in theories with compact extra dimensions where fermionic chiral zero modes have different localizations. This is the case in many warped extra dimension models where the right-handed top quark is…
We investigate a possible CP violating effect in $e^+e^-$ annihilation into $t\bar t$ top quark pairs. As an illustrative example, we assume the source of the CP nonconservation is in the Yukawa couplings of a neutral Higgs boson which…
We describe the latest results obtained by the CMS Collaboration on top quark spin and polarization properties. The top quark spin asymmetry is measured both targeting single-top quark production in the $t$-channel and single-top quark…
We study the effects of gluon radiation on top production and decay processes at an $e^+e^-$ collider.The matrix elements are computed without any approximations, using spinor techniques. We use a Monte Carlo event generator which takes…
We provide a framework for the analysis of the W boson helicity in the decay of the top quark that is based on a general effective tbW coupling. Four independent coupling coefficients can be uniquely determined by the fractions of…
CP-violating asymmetries in the processes e+e- -> t tbar and gamma gamma -> ttbar can provide information about CP-violating couplings of the top quark, whose presence would signal physics beyond the standard model. Work on studies of…
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…