Related papers: T-odd asymmetries in radiative top-quark decays
In the presence of an electric dipole coupling of $t \bar t$ to a photon, and an analogous ``weak" dipole coupling to the $Z$, $CP$ violation in the process $e^+e^- \rightarrow t \bar t$ leads to the polarization of the top and anti-top.…
The calculation of the partial width of the rare t-quark decay into Upsilon-meson, W-boson and b-quark (t -> \Upsilon W b) is presented. The branching ratio equals Br(t -> Upsilon W b) = 1.3 * 10^{-5} that make possible searches for this…
We investigate several quantities, defined in the decays of top quark pairs, which can be used to explore non-standard Wtb interactions. Two new angular asymmetries are introduced in the leptonic decay of top (anti)quarks. Both are very…
We discuss top quark production and its subsequent decay for searching new physics at lepton colliders. The angular dependence of the decay leptons is calculated including both QCD corrections and anomalous gamma Z - t tbar couplings. The…
Order-alpha_s QCD corrections in the soft-gluon approximation to angular distributions of decay charged leptons in the process e+e- -> t tbar, followed by semileptonic decay of t or tbar, are obtained in the e+e- centre-of-mass frame. As…
We study the lepton angular distributions in $B\to D^{(*)} \ell \nu_{\ell}$ decays. The lepton angular asymmetries in the decays with the general effective interactions are examined. We demonstrate that the asymmetries are sensitive to new…
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 identify the $T$-odd structure functions that appear in the description of polarized top quark decays in the sequential decay $t(\uparrow) \to X_b+W^+(\to \ell^+ + \nu_\ell)$ (two structure functions) and the quasi-three-body decay…
The angular and energy distributions of the final lepton in e ebar t tbar --> l^{+-} X at next linear colliders (NLC) are analyzed a model-independent way for arbitrary longitudinal beam polarizations as sensitive tests of possible…
We present the complete calculation of the top-quark decay width at next-to-next-to-leading order in QCD, including next-to-leading electroweak corrections as well as finite bottom quark mass and $W$ boson width effects. In particular, we…
We investigate the possibility that an imaginary anomalous $tbW$ coupling can be measured in the process $e^-p \to \nu_e \overline t X$ by means of T-odd observables. One such observable considered here is the polarization of the top…
We present a computation of QCD next-to-leading order corrections to the top production and decay process at linear colliders. The top quarks are allowed to be off-shell and the production and decay subprocesses are treated together, thus…
We revisit the effect of CP violating anomalous top-quark couplings in $t\bar{t}$ production and decay. We consider $t\bar{t}$ production through gluon fusion (and light $q{\bar q}$ annihilation) followed by top-quark decay into $bW$ or…
The fragmentation function of a scalar leptoquark into possible S-wave bound states with a heavy anti-quark is calculated to the leading order in perturbative QCD for the high energy processes at large transverse momenta. The one-loop…
We describe a calculation of the fully-differential decay rate of a top quark to a massless $b$-quark and a lepton pair at next-to-next-to-leading order in perturbative QCD. Technical details of the calculation are discussed and selected…
Analytic formulae are given for order alpha_s perturbative QCD corrections to the double differential distribution of the tau lepton energy and the invariant mass of the tau + antineutrino system in semileptonic decays of the bottom quark.…
An optimal-observable analysis of the angular and energy distributions of the leptons and bottom quarks in the process e+e- --> tt-bar --> l^{+-}/b(b-bar)... has been performed in order to measure the most general top-quark couplings to…
We obtain predictions for $B_{(s)}\to e^+e^-\gamma$ and $B_{(s)}\to \mu^+\mu^-\gamma$ decays. All the contributions containing long-distance QCD effects are calculated in the framework of relativistic quark model. The contributions of the…
We study the effects of T-odd interactions of top-quark via the pair production of top-quark in the semileptonic detection modes at the Large Hadron Collider by means of the T-odd observables constructed through the momenta of the observed…
Corrections of $O(\alpha_s^2)$ to the decay of the top quark into a W boson and a bottom quark are calculated. The method is based on an expansion of the top quark propagator for small external momentum, q, as compared to the top quark…