Related papers: Study of the Top Quark FCNC
A new constraint is obtained on the CP-violating flavor mixing between the left-handed top scalar quark (\tilde{t}_L) and charm scalar quark (\tilde{c}_L), by considering a chargino loop contribution to chromo-electric dipole moment of…
Flavor changing neutral currents coming from a new non-universal neutral Gauge-Boson and from the non-unitary quark mixing matrix for the $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ model with right handed neutrinos are studied. By imposing as…
We show that supersymmetric $R$-parity breaking ($\not R_p$) interactions always result in Flavor Changing Neutral Current (FCNC) processes. Within a single coupling scheme, these processes can be avoided in either the charge $+2/3$ or the…
A search for flavor-changing neutral currents (FCNC) in events with the top quark and the Higgs boson is presented. The Higgs boson decay to a pair of b quarks is considered. The data sample corresponds to an integrated luminosity of 35.9…
I consider neutron electric dipole moment contributions induced by flavor changing Standard Model Higgs boson couplings to quarks. Such couplings might stem from non-renormalizable $SU(2)_L \times U(1)_Y$ invariant Lagrange terms of…
Considering the experimental constraints given by CMS collaboration at $\sqrt{s} = 8$ TeV on the strength of top quark flavour-changing neutral-current (FCNC) couplings $tq\gamma$ and $tqg$, we investigate the production of top quark in…
We have used the Collider Detector at Fermilab (CDF II) to search for the flavor-changing neutral-current (FCNC) top quark decay ${t\goes Zc}$ using a technique employing ratios of $W$ and $Z$ production, measured in \ppbar data…
Processes involving flavor changing neutral currents (FCNC) provide excellent signatures with which to search for evidence of new physics. They have very small branching fractions in the Standard Model since they are highly suppressed by…
We calculate first-order QCD corrections to the cross section for single top quark production mediated by flavor changing neutral currents (FCNC) in ep collisions at the HERA collider. We find that the uncertainty due to the choice of the…
The observed flavor-changing neutral-current (FCNC) processes in the standard model (SM) arise from the loop diagrams involving the weak charged currents mediated by the $W$-gauge boson. Nevertheless, the top-quark FCNCs and lepton-flavor…
We discuss the Flavor-Changing Neutral Current (FCNC) decays of the top quark t -> c Vi Vj (Vi=gamma, Z, g) in the framework of the Standard Model (SM) and in a two-higgs doublet model (2HDM) with tree-level FCNC couplings. While in the SM…
In supersymmetry (SUSY) the flavor mixing between top-squark (stop) and charm-squark (scharm) induces the flavor-changing neutral-current (FCNC) stop decay $\tilde t_1 \to c \tilde \chi^0_1$. Searching for this decay serves as a probe of…
A search for flavour-changing neutral currents (FCNC) processes in proton-proton ($pp$) collisions at a centre-of-mass energy of 13 TeV with the ATLAS detector at the CERN Large Hadron Collider (LHC) is presented. The analysed data…
Searches for flavor changing neutral current (FCNC) processes in top-quark production and decays by the ATLAS Collaboration are presented. Data collected from $pp$ collisions at the LHC at a centre-of-mass energy of 7 TeV during 2011,…
We study the nature of the flavor changing neutral couplings of the top quark with the Higgs boson and the up/charm quark in the $t\bar{t}$ production at linear colliders. There are previous bounds on such tqH couplings at both, linear and…
In this paper, we investigated the process $pp \to W^{-}hj$ induced by the top-Higgs flavor changing neutral current (FCNC) couplings at the LHC. We found that the cross section of $pp \to W^{-}hj$ mainly comes from the resonant process…
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…
In this thesis we discuss the combined effects of strong and electroweak FCNC effective operators in top quark physics at the CERN LHC and lepton flavour violation at the ILC with dimension six effective operators.
Flavor nonconserving and CP violating effects of the quark mixings are investigated in electroweak models incorporating singlet quarks. Especially, the D^0 - {\bar D}^0 mixing and the neutron electric dipole moment, which are mediated by…
We discuss the existing limits on top flavour-changing neutral couplings in models with new vector-like quarks. Large hadron and e+ e- colliders can improve these bounds by more than one order of magnitude.