Related papers: Spin Correlations in Top Quark Production at e^+ e…
Theoretical results are presented for top quarks produced in annihilation of polarized electrons on positrons. Polarization studies for $t\bar t$ pairs near threshold are free from hadronization ambiguities. This is due to the short…
We investigate the spin correlations between production and decay in the process where dark photons $A'$ are produced in pseudoscalar meson decays, for example, $\pi^0, \eta \to \gamma A'$, and then decay to fermion pairs, $A' \to f…
Several topics of relevance to low transverse momentum $\psi$ and $\chi_{1,2}(c\overline{c})$ production in polarized proton-proton collisions are discussed. The leading ${\cal O}(\alpha_S^3)$ contributions to the low $p_T$ $\chi_1$…
Once new particles are discovered at the LHC and their masses are measured, it will be of crucial importance to determine their spin, in order to identify the underlying new physics model. We investigate the method first suggested by Barr…
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…
The heaviest known elementary particle today, the top quark, has been discovered in 1995 by the CDF and D0 collaborations at the Tevatron collider at Fermilab. Its high mass and short lifetime, shorter than the timescale for hadronization,…
We calculate the QCD radiative corrections to the production of supersymmetric scalar partners of quarks in e+e- annihilation. We include both the standard gluonic corrections and the genuine supersymmetric QCD corrections due to…
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…
We review the most recent results on top quark production at the Tevatron including the measurements of the top quark pair ($t \bar t$) production cross section, the forward-backward asymmetry, the spin correlations and the ratio of…
Polarization and spin correlations have been studied in detail for top quarks at the LHC, but have been explored very little for the other flavors of quarks. In this paper we consider the processes $pp\to q\bar{q}$ with $q = b$, $c$ or $s$.…
We present the azimuthal correlations in the decay products of the top quark pair created in the process $gg \to t \tbar \to b \bbar \wplus \wminus$ calculated in leading-order QCD. We then discuss deviations in this distribution that could…
The specific effects of the reflective scattering (antishadowing) related to the spin correlations in the top quark production at the LHC are considered. Account for those effects is important in the searches for the signatures of the extra…
The effect of single top production on the study of top quark pair production in future high energy electron--positron colliders is evaluated. The rate of the single top quark production process is sizeable throughout a large range of…
We report on our results about hadronic $t\bar t$ production at NLO QCD including $t, \bar t$ spin effects, especially on $t\bar t$ spin correlations.
We show that studying the single top quark production via the $W$--gluon fusion process can provide unique information on: (i) the measurement of the decay width $\width$; (ii) probing the symmetry breaking mechanism by measuring the form…
Measurements of several top-quark properties obtained from CMS data collected at various centre-of-mass energies are presented. The results include measurements of the top pair charge asymmetry, $\textrm{t}\bar{\textrm{t}}$ spin…
The spin of supersymmetric particles can be determined at $e^+e^-$ colliders unambiguously. This is demonstrated for a characteristic set of non-colored supersymmetric particles -- smuons, selectrons, and charginos/neutralinos. The analysis…
We propose to measure the threshold lepton asymmetry, that is the forward-backward asymmetry of the charged lepton in ttbar events near the production threshold. At threshold top quark pairs are produced in an s-wave. Angular momentum…
We compute the next-to-next-to-leading order (NNLO) QCD corrections to the decay $t(\uparrow) \to X_b +W^+$ of a polarized top quark. The spin-momentum correlation in this quasi two-body decay is described by the polar angle distribution…
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…