Related papers: Why e+ e- to T Tbar is Different
We show that top-quark pairs are produced in an essentially unique spin configuration in polarized $e^+e^-$ colliders at all energies above the threshold region. Since the directions of the electroweak decay products of polarized top-quarks…
The top quark pairs produced at a polarized muon collider are in a (nearly) pure spin configuration. This result holds for all center-of-mass energies, and is insensitive to the next-to-leading order QCD radiative corrections. The decay…
The object of this thesis is to study the spin-spin correlations for top quark productions and their decay at polarized e^+e^- linear colliders. For the analyses of the spin-spin correlations in top quark production, we introduce a generic…
We analyze spin correlations between top quark and anti-top quark produced at polarized e^+ e^- and gamma gamma colliders. We consider a generic spin basis to find a strong spin correlation. Optimal spin decompositions for top quark pair…
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…
Angular distributions of a mu+ and a b-quark resulting from the decay of a top quark produced at the e+e- linear collider with an unpolarized and a 100% longitudinally polarized electron beam are presented. The results of the standard model…
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 weak decay of a polarized top quark has a rich structure of angular correlations among its decay products. We describe some of the noteworthy features of such decays. We then examine the three modes of single top production, with an…
Top quark pair production is presented at a polarized Muon Collider above the threshold region. The off-diagonal spin basis is the natural basis for this discussion as the top quark pairs are produced in an essentially unique spin…
Top quark pair production by (polarized) gamma gamma collisions offers an interesting testing ground of the Standard Model and its extensions. In this Letter we present results for differential cross sections of top quark pair production…
We investigate the degree of spin polarization of single top quarks in the $e\gamma$ collision via the process $e^{+} \gamma \to t \bar{b} \bar{\nu_{e}}$ with center of mass energies $\sqrt{s}$=0.5, 1 and 1.5 TeV of the parental linear…
The effect of anomalous chromoelectric couplings of the gluon to the top quark are considered in e+ e- --> t tbar. The total cross section, as well as t and tbar polarizations are calculated to order alpha_s in the presence of the anomalous…
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…
We investigate spin properties of single top quark production at hadron colliders. Based on an analogy with single top production and polarized top quark decay, we reproduce in a simple way the results by G.Mahlon and S.Parke on the…
We discuss the degree of spin polarization of single top quarks produced via $Wg$ fusion process in $ep$ collision at TESLA+HERAp and CLIC+LHC energies $\sqrt{s}=1.6$ and 5.3 TeV. For $eb \to t \bar{\nu}$ subprocess we show that the top…
We discuss the spin properties of top quark pairs produced at hadron colliders at next-to-leading order in the coupling constant alpha_s of the strong interaction. Specifically we present, for some decay channels, results for differential…
We describe the off-diagonal spin basis for observing angular correlations in top quark pair production events at the Fermilab Tevatron. For events initiated by quark-antiquark annihilation, the top and antitop quark spins are 100%…
We discuss top quark production and its subsequent decay at lepton colliders including both QCD corrections and anomalous gamma / Z - t t-bar couplings. The off-diagonal spin basis for the top and anti-top quarks is shown to be useful to…
Recent results on production and decays of polarized top quarks are reviewed. Top quark pair production in $e^+e^-$ annihilation is considered near energy threshold. For longitudinally polarized electrons the produced top quarks and…
We investigate the feasibility of probing anomalous top-quark couplings of $Wtb$, $Z t \bar{t}$, and $\gamma t \bar{t}$ in terms of an effective Lagrangian with dimension-six operators at future $e^+e^-$ linear colliders with a c. m. energy…