Related papers: The process $e^{+}e^{-}\to \bar{t}c$ in topcolor-a…
In the framework of topcolor-assisted technicolor model we calculate the contributions from the pseudo Goldstone bosons and new gauge bosons to $e^+e^- \to t\bar{t}$. We find that, for reasonable ranges of the parameters, the pseudo…
We study the rare top decays $t\to c l_{i} l_{j}(l=\tau,\mu,or e)$ in the framework of topcolor-assisted technicolor($TC2$) models. We find that the neutral top-pion $\pi_{t}^{0}$ can produce significant contributions to these processes via…
In the framework of topcolor-assisted technicolor(TC2) model, we study a neutral toppion production process $e^{-}\gamma\to e^{-}\Pi^{0}_{t}$ in this paper. Our results show that the production cross section of $e^{-}\gamma\to…
We report on the first search for top-quark production via flavor-changing neutral-current (FCNC) interactions in the non-standard-model process u(c)+g -> t using ppbar collision data collected by the CDF II detector. The data set…
It is argued that the topcolor models recently proposed by Hill [1] may face significant constraints from flavor-changing neutral current processes (such as $B-\bar{B}$ mixing) unless the mixing angles between down-type quarks are small.…
We examine the subprocess $\gamma\gamma \to t\bar{c}+\bar{t}c$ at electron-positron colliders in the two-Higgs-doublet model with flavor-changing scalar couplings, where all the one-loop contribuions are considered, and the results are…
In the context of topcolor-assisted techicolor(TC2) models, we study the contributions of the neutral top-pion $\pi^{0}_{t}$ to the lepton flavor violating(LFV) processes $l_{i}\to l_{j}\gamma$ and $l_{i}\to l_{j}l_{k}l_{l}$. We find that…
The topcolor-assisted technicolor (TC2) model predicts the existence of the charged top-pions ($\pi_t^\pm$), whose large couplings with the third generation fermions will induce the charged top-pion production associated with the bottom and…
We consider the contributions of the extra gauge boson Z' to the like sign $\tau$ production process $e^-\gamma\to e^+(\mu^+)\tau^-\tau^-$, induced by the tree-level flavor changing interactions. Since these rare production are far below…
Decays of the top quark induced by flavor changing neutral currents (FCNC) are known to be extremely rare events within the Standard Model. This is so not only for the decay modes into gauge bosons, but most notably in the case of the Higgs…
A study of the top quark interactions via flavour-changing neutral current (FCNC) processes provides an intriguing connection between the heaviest elementary particle of the standard model (SM) of particle physics and the new scalar bosons…
Top quark flavor changing neutral current (FCNC) interactions are highly suppressed in the Standard Model. Therefore, any large signal of FCNCs will indicate the existence of new interactions. In this paper, searches for FCNC interactions…
We evaluate the top-quark FCNC productions induced by the topcolor assisted technicolor (TC2) model at the LHC. These productions proceed respectively through the parton-level processes g g -> t c_bar, c g->t, c g -> t g, c g -> t Z and c g…
In the topcolor-assistant technicolor (TC2) model, the typical physical particles, top-pions and top-Higgs, are predicted and the existence of these particles could be regarded as the robust evidence of the model. These particles are…
In the framework of topcolor-assisted technicolor (TC2) theory, we calculate the contributions of the scalars(the neutral top-pion $\pi_{t}^{0}$ and the top-Higgs $h_{t}^{0}$) to the flavor-changing rare top decays $t\to c V V$(V= W, g,…
We present a search for flavor changing neutral currents (FCNC) in decays of top quarks. The analysis is based on a search for $t\bar{t}\rightarrow\ell'\nu\ell\bar{\ell}$+jets ($\ell, \ell' = e,\mu$) final states using 4.1 {\rm fb}$^{-1}$…
We compute the flavor changing neutral current process $B \to X_s \mu^+ \mu^-$ in technicolor models with scalars. We find that the branching ratio can be enhanced relative to that of the Standard Model by as much as 60%. The full parameter…
The reactions e+e- -> t bar-c nu_e bar-nu_e, t bar-c e+ e- are very sensitive probes of the flavor-changing-scalar couplings which can occur in a model with one extra Higgs doublet. At the Next Linear Collider, with a center of mass energy…
Large top quark flavor changing through neutral currents is expected by many extensions of the standard model. Direct and indirect searches for flavor changing neutral currents (FCNC) in the top quark decays to an up type quark (up,charm)…
The flavor changing neutral current tcV (V=\gamma,Z) couplings in the production vertex for the process $e^+e^-\to t\bar c$ or $\bar t c$ in the standard model are investigated. The precise calculations keeping all quark masses non-zero are…