Related papers: CP violation in top pair production at an e^+e^- c…
Top quark is extremely sensitive to non-standard CP violating phases. General strategies for exposing different types of phases at the NLC are outlined. SUSY phase(s) cause PRA in $t\to Wb$. The transverse polarization of the $\tau$ in the…
The framework of Higgs-dependent Yukawa couplings allows one to eliminate small couplings from the Standard Model, which can be tested at the LHC. In this work, I study the conditions for CP violation to occur in such models. I identify a…
We consider supersymmetric extensions of the standard model with two pairs of Higgs doublets. We study the possibility of spontaneous $CP$ violation in these scenarios and present a model where the origin of $CP$ violation is soft, with all…
We discuss associated production of a Higgs boson with a pair of $t {\bar t}$ quarks at a future high energy $e^+e^-$ collider. The process $e^+e^-\to t {\bar t}h$ is particularly sensitive to the presence of new physics and we consider the…
The completion of the third-order QCD corrections to the inclusive top-pair production cross section near threshold demonstrates that the strong dynamics is under control at the few percent level. In this paper we consider the effects of…
We describe how to probe new physics through large CP violation effects and non--standard Z-t-t couplings via the scattering process e^-e^+ -> t tbar. [Talk presented at the Workshop on Physics and Experiments with Linear $e^+e^-$…
We review the production of scalar Higgs-like particles in high-energy electron-electron collisions, via the fusion of electroweak gauge bosons. The emphasis is on how to distinguish a CP-even from a CP-odd Higgs particle. Among the more…
CP violation induced by resonant transitions of a scalar to a pseudoscalar intermediate state is analyzed within a gauge-invariant resummation approach based on the pinch technique. Necessary conditions governing the resonant enhancement of…
The polarization asymmetries of $t$, $\bar t$ quarks can be used in the reaction $e^+e^-\to t\bar t\nu_e\bar\nu_e$ to measure the Higgs width, in the Standard Model or in its extensions, and to search for non-standard CP violating phases.…
Strictly within the standard electro-weak interaction, CP violation in the flavour conserving process $\eta \ra \pi + \pi $ could originate from the mixing of the $\eta$ meson with the virtual scalar Higgs $ H^{0}$ via $ W^{+}+W^{-}$ and…
We study possible CP-violation effects of the Higgs to $Z$-boson coupling at a future $e^+ e^-$ collider, e.g. the International Linear Collider (ILC). We find that the azimuthal angular distribution of the muon pair, produced by $e^+ e^-…
The $CP$ properties of the coupling between the Higgs boson and the top quark are investigated with 139 fb$^{-1}$ of proton-proton collision data recorded by the ATLAS experiment at the LHC at a centre-of-mass energy of $\sqrt{s}=13$ TeV.…
We study the possibility to test CP invariance in the $W^+W^-$ production via photon fusion at NLC. The predictions of the CP violation effects are made within two Higgs doublet extensions of the minimal standard model, where CP violation…
The effect of new operators that give rise to CP-violating couplings of the type $Z t \bar{t}$ and $\gamma t \bar{t}$ are examined at future electron positron Linear Colliders (FLC). The impact of these CP-violating interactions over…
Models with an extended scalar sector may in principle provide new sources of CP violation originating in the scalar potential. One of the simplest ways to implement this idea is to have CP violation in a two-Higgs-doublet model. Here, it…
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…
In a general two-scalar-doublet model without fermions, there is a unique source of CP violation, $ J_1 $, in the gauge interactions of the scalars. It arises in the mixing of the three neutral physical scalars $ X_1 $, $ X_2 $ and $ X_3 $.…
We obtain analytic formulae for the cross section of the sequential processes of $e^+ e^- \to t \bar t$ and $t \to b l \nu$ in the laboratory frame where the dependence on triple product correlations of the type ($\hat(q}_1 x \hat{q}_2 .…
We explore CP violating aspects in the Higgs sector of models where new vectorlike quarks carry Yukawa couplings mainly to the third generation quarks of the Standard Model. We point out that in the simplest model, Higgs CP violating…
The conjoined production at the LHC of single top and Higgs boson via $t$-channel weak boson exchange is ideal to probe the top-quark Yukawa coupling, due to a delicate cancellation between the amplitudes with the $htt$ and the $hWW$…