Related papers: Rare top quark decays in extended models
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…
In the paper, we discuss the possibility of observation of heavy quarkoniums via the processes involving flavor changing neutral currents (FCNC). More explicitly, we systematically calculate the production of heavy charmonium and…
A study of the top quark \emph{Flavour Changing Neutral Current} (FCNC) through $Z$-boson has been performed in the proposed future $e^-p$ collider for the energy, $E_{e(p)} = 60~(7000)$~GeV. We considered an effective theory where the…
Dark Matter (DM) is a known unknown. Apart, current experimental constraints on flavor-changing neutral current (FCNC) processes involving up-type quarks also provide scope to explore physics beyond the Standard Model (SM). In this article,…
We review the theory and experimental measurements in the flavour changing neutral current (FCNC) processes involving B decays in the context of the standard model (SM). The role of these processes in determining the weak mixing matrix…
The dimuon and dielectron data from the Tevatron $\bar pp$ collider are used to probe for heavy quarks, which decay dominantly via flavour changing neutral current. Depending on whether the $FCNC$ decay occurs at the tree or loop level, one…
Rare charm decays offer the unique possibility to explore flavour-changing neutral-currents in the up-sector within the Standard Model and beyond. Due to the lack of effective methods to reliably describe its low energy dynamics, rare charm…
In this study, we investigate anomalous flavour-changing neutral current (FCNC) interactions related to the top quark, particularly the $t\rightarrow q\gamma$ transition, within the Standard Model Effective Field Theory (SMEFT) framework.…
Extensions of the standard model (SM) with gauge symmetry SU(3)_c X SU(4)_L X U(1)_X (3-4-1 extensions) where anomaly cancellation takes place between the fermion families (three-family models) predict the existence of two new heavy neutral…
We study the implications of flavour-changing neutral currents (FCNC's) in a model with the $SU(2)_l\times SU(2)_h\times U(1)_Y$ electroweak gauge symmetry for several anomalies appearing in $b\to s \ell\bar \ell$ induced $B$ decays in LHCb…
D0 and CDF collaborations at the Fermilab Tevatron have searched for non-standard-model single top-quark production and set upper limits on the anomalous top quark flavor-changing neutral current (FCNC) couplings $\kappa^g_{tc}/\Lambda$ and…
The flavor changing neutral current (FCNC) transitions t --> q'H and t --> q'V_i (V_i=\gamma, g, Z) are studied in the context of the effective Lagrangian approach. We focus on the scenario in which these decays are predominantly induced by…
We study flavor changing neutral current decays of the top quark in the context of general warped extra dimensions, where the five dimensional metric is slightly modified from 5D anti-de-Sitter (AdS$_5$). These models address 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…
In the so called two Higgs doublet model for the top-quark (T2HDM), first suggested by Das and Kao, the top quark receives a special status, which endows it with a naturally large mass, and also potentially gives rise to large flavor…
We analyse a class of two Higgs doublet models where flavour-changing neutral currents (FCNC) are present at tree level in a mixing-suppressed manner. In this class of models, because of a discrete symmetry imposed on the lagrangian, the…
Despite the tremendous success of the Standard Model, the arguments for the necessity of an extension are compelling. An attractive option is provided by Two-Higgs-Doublet models, due to their simplicity and them being the low-energy limit…
We investigate a family-nonuniversal Abelian extension of hypercharge, which significantly alters the phenomenological features of the standard model. Anomaly cancellation requires that the third quark family transforms differently from the…
We investigate the prospects of discovering the top quark decay into a charm quark and a Higgs boson ($t \to c h^0$) in top quark pair production at the CERN Large Hadron Collider (LHC). A general two Higgs doublet model is adopted to study…
Flavour-changing neutral currents are extremely rare processes in the standard model that can be sensitive to various new physics effects. The summary of the latest experimental results from the LHC experiments is given. Preliminary results…