Related papers: Probing top flavour-changing neutral couplings at …
We perform a global analysis of the sensitivity of LEP2 and e^+e^- colliders with a c.m. energy in the range 500 - 2000 GeV to new flavor-changing single top quark production in the effective Lagrangian approach. The processes considered…
Within the model-independent framework of $SU(3)\times SU(2)\times U(1)$ gauge-invariant dimension-six operators, we study flavor-changing $Wtq$ couplings ($q=d,s$) and related four-quark contact interactions involving the top. We obtain…
The discovery potential and diagnostic abilities of proposed future colliders for new heavy neutral ($Z'$) and charged ($W'$) gauge bosons are summarized. Typical bounds achievable on $M_{Z',W'}$ at the TEVATRON, DI-TEVATRON, LHC, 500 GeV…
Lepton flavor violation is one of the cleanest probes of physics beyond the standard model. In this work, we explore the sensitivity of the process $e^+ e^- \to \tau \mu$ to new physics above the TeV scale at the proposed circular…
Photon colliders (gamma-gamma, gamma-e) are based on backward Compton scattering of laser light off the high energy electrons of linear colliders. Recent study has shown that the gamma-gamma luminosity in the high energy peak can reach…
The general features of the Moller scattering and its use as an electron polarimeter are described and studied in view of the planned future high energy e^+e^- linear colliders. In particular the study concentrates on the TESLA collider…
We consider the possibility of observing deviations from the Standard Model gauge-boson self-couplings at future $e\gamma$ colliders. We concentrate on the process $e^-\gamma \rightarrow \nu W^- Z$, which is particularly sensitive to the…
During the LEP2 period the e+e- collider increased its center of mass energy from 161 GeV to 209 GeV and a total integrated luminosity of approximately 700 pb-1 was recorded per experiment. Pairs of W bosons are produced and allow the study…
We study the rare top-quark decay t->ch, where h is a generic Higgs boson, at a linear collider. If kinematically accessible, all models contain this decay at some level due to quark flavor mixing. Some models, such as Model III of the…
Proton-proton interactions resulting in final states with two photons are studied in a search for the signature of flavor-changing neutral current interactions of top quarks (t) and Higgs bosons (H). The analysis is based on data collected…
Top quark production in the process $e^+e^- \rightarrow t\bar{t}$ at a future linear electron positron collider with polarised beams is a powerful tool to determine indirectly the scale of new physics. The presented study, based on a…
A study of single top quark production via flavor changing neutral current interactions at $tq\gamma$ vertices is performed at future circular hadron electron collider. The signal cross sections for the processes $e^{-}p\to e^{-}W^{\pm}q+X$…
Present evidences for neutrino masses and lepton flavour mixings allow to predict, in the Standard Model with light neutrinos, branching rates for the decays Z --> e mu, mu tau, e tau of less than 10^{-54}, while present experimental…
We present the sensitivity to Flavor Changing Neutral Currents (FCNC) in interactions involving the top quark at future $e^+e^-$ and $\mu^+\mu^-$ machines. We consider the $Ztc$ vertex as well as four-fermion contact interactions involving…
A search for flavor-changing neutral current (FCNC) processes in associated production of a top quark and Higgs boson, with the Higgs boson decaying to a pair of b quarks, is presented. To experimentally probe the top-Higgs FCNC couplings,…
We explore the use of polarized $e^+/e^-$ beams and/or the information on final state decay lepton polarizations in probing the interaction of the Higgs boson with a pair of vector bosons. A model independent analysis of the process $e^+…
A future linear collider such as TESLA may be able to run on the Z0 resonance with very high luminosity and polarised electron and positron beams. The possibilities of measuring electroweak quantities with high precision are investigated.…
We explore the top quark flavor-changing 4-Fermi interactions ($tuee$ and $tcee$) with scalar, vector, and tensor structures using machine learning models to analyze tri-lepton processes at the LHC. The study is performed using $t\bar{t}$…
A general two Higgs doublet model (2HDM) is adopted to study the signature of flavor changing neutral Higgs (FCNH) decay $\phi^0 \to t\bar{c}+\bar{t}c$, where $\phi^0$ could be a CP-even scalar ($H^0$) or a CP-odd pseudoscalar ($A^0$).…
In this paper, we examine the sensitivity of the three-top quark production at the LHC to the top quark flavor-changing neutral currents (FCNC) as well as the sensitivity of the four-top production to the strong and weak dipole moments of…