Related papers: Probing top flavour-changing neutral couplings at …
Measuring top polarization is extremely important in understanding any new physics that couples to top quark. Here, we take up the task of extracting polarization of top quark coming from TeV-scale stop decay at the upgraded high luminosity…
We study possible non-standard $tuZ$ and $tcZ$ couplings, which induce flavor-changing neutral-current decays of the top quark, in the effective-Lagrangian framework. The corresponding interaction Lagrangian comes from several $SU(3) \times…
The LHC will have unprecedented sensitivity to flavor-changing neutral current (FCNC) top quark decays, whose observation would be a clear sign of physics beyond the standard model. Although many details of top flavor violation are model…
In this paper, we study the anomalous flavor changing neutral current Yukawa interactions between the top quark, the Higgs boson, and either an up or charm quark ($\rm tqH, q=u, c$). We probe these couplings in $\rm e^- p\rightarrow \nu_e…
A search for flavour-changing neutral current decays of a top quark into an up-type quark ($q=u, c$) and the Standard Model Higgs boson, $t\rightarrow Hq$, is presented. The search is based on a dataset of $pp$ collisions at $\sqrt{s}=13$…
We estimate the sensitivity to the top-quark Yukawa coupling $y_t$ at future $e^+e^-$ colliders. We go beyond the standard approach that focuses on $t\bar t h$ production and consider final states with a Higgs boson but not top quarks. 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. A description on how to combine the cross sections of…
The main possibilities of investigation of leptons and bosons birth in interaction of polarized photons are considered. The usage of $\gamma \gamma \to f \bar{f} [+\gamma]$ reactions for the luminosity measurement on linear photon collider…
A search for the Higgsstrahlung process e+e- -> hZ is described, where the neutral Higgs boson h is assumed to decay into hadronic final states. In order to be sensitive to a broad range of models, the search is performed independent of the…
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…
We study the anomalous production of a single top quark in association with a Higgs boson at the LHC originating from flavor changing neutral current (FCNC) interactions in $tqg$ and $tqH$ vertices. We derive the discovery potentials and…
We study the LHC phenomenology of flavor changing Yukawa couplings between top quark, Higgs boson, and either an up or charm quark. Such $tuh$ or $tch$ couplings arise for instance in models in which Higgs sector is extended by the…
Many extensions of the standard model predict the existence of extra neutral vector bosons, generically referred as $Z^\prime$. This boson may be discovered at the LHC but in this case it will be necessary to study the respective parameters…
Searches for rare processes such as mu --> e gamma put stringent limits on lepton flavour violation expected in many Beyond the Standard Model physics scenarios. This usually precludes the observation of flavour violation at high energy…
TeV-scale $Z^\prime$ bosons with family-dependent couplings can explain some anomalies inferred from $B-$meson measurements of processes involving the $b \rightarrow s \ell^+\ell^-$ transition. A $Z^\prime$ originating from…
We present a search for flavor changing neutral currents in decays of top quarks. The analysis is based on a search for ttbar -> l'null + jets (l, l' = e, mu) final states using 4.1 fb^-1 of integrated luminosity of ppbar collisions at…
We study the potential of an $e^+e^-$ linear collider to search for neutralino-neutralino-photon production. Our analysis shows that this signal is not viable under realistic expectations for electron beam polarization due to large Standard…
We propose to utilize the exclusive $Z$-boson rare decays $Z\to \Upsilon(ns)+\gamma$ to constrain the $Zb\bar{b}$ couplings at the HL-LHC and 100 TeV proton-proton collider. We demonstrate that the event yield of the proposed processes is…
The scalar top discovery potential has been studied for the TESLA project with a full-statistics background simulation at sqrt(s)=500 GeV and L=500 fb-1. The beam polarization is very important to measure the scalar top mixing angle and to…
A search for single top production in ep collisions using the complete high energy data from HERA is presented. This search is based on the analysis of events containing isolated leptons (electrons or muons) and missing transverse momentum…