Related papers: Signals from Flavor Changing Scalar Currents at th…
In the most general two-Higgs doublet model (generally referred to as Model III), tree level flavor changing neutral couplings exist. It has been noted that the most natural value for such a coupling is of the order of the geometric mean of…
We define a new class of Z' models with neutral flavour-changing interactions at tree level in the down-quark sector. They are related in an exact way to elements of the quark mixing matrix due to an underlying flavoured U(1)' gauge…
The charged fermion mass matrices are always invariant under $U(1)^3$ symmetry linked to the fermion number transformation. A class of two Higgs doublet models (2HDM) can be identified by requiring that the definition of this symmetry in an…
In this letter we show a general description about flavor-changing neutral currents (FCNC) mediated by scalars. The analysis is extended at two-loop level for the Two-Higgs Doublet Model type-III because others models have strong…
We study quark flavor violating interactions mediated by the Higgs boson $h$. We consider observables involving a third generation quark, of both the up and the down quark sectors, like $h\rightarrow bs$ and $t\rightarrow ch$. Using an…
The meaning of non-abelian super flavorsymmetry in the presence of Multiple Higgs Doublets is twofold: The first one is to order the Yukawa sector of the standard model, while generating the Cheng-Sher suppression of tree-level Flavor…
We investigate the possible presence of Flavor Changing Neutral Current (FCNC) couplings of the top quark with gluon and photon through $e^-p\to e^-tj$ process at the Future Circular Collider in the proton-electron mode (FCC-he). Focusing…
We analise phenomenological implications of two Higgs doublet models with Higgs flavour changing neutral currents suppressed in the quark sector by small entries of the Cabibbo-Kokayashi-Maskawa matrix. This suppression occurs in a natural…
Top quark and Higgs boson decays induced by flavor-changing neutra currents (FCNC) are very much suppressed in the Standard Model (SM). Their detection in colliders like the Large Hadron Collider (LHC), Next Linear Collider (NLC) or…
The tree-level flavour-changing neutral currents in the two-Higgs-doublet models can be suppressed by protecting the breaking of either flavour or flavour-blind symmetries, but only the first choice, implemented by the application of the…
We explore Two Higgs Doublet Models with non-standard flavor structures. In analogy to the four, well studied, models with natural flavor conservation (type 1, type 2, lepton-specific, flipped), we identify four models that preserve an…
Many new physics scenarios beyond the Standard Model often necessitate the existence of a (light) neutral scalar $H$, which might couple to the charged leptons in a flavor violating way, while evading all existing constraints. We show that…
If the LHC should fail to observe direct signals for new physics, it may become necessary to look for new physics effects in rare events such as flavour-changing decays of the top quark, which, in the Standard Model, are predicted to be too…
A three Higgs-doublet model admitting an $S_3$-symmetry can predict the observed pattern of the quark masses and their mixings. However the same symmetry also introduces potential flavour-changing neutral currents at the tree level. We…
The subprocess $gg \to t\bar{c}+\bar{t}c$ in the two-Higgs-doublet model with flavor-changing scalar couplings is examined at the one loop level. With perturbative QCD factorization theorem, the corresponding cross sections for…
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.
Testing the properties of the Higgs particle discovered at the LHC and searching for new physics signals, are some of the most important tasks of Particle Physics today. Current measurements of the Higgs couplings to fermions and gauge…
We present a search for flavor changing neutral currents via quark-gluon couplings in a sample of single top quark final states corresponding to 2.3 fb^-1 of integrated luminosity collected with the D0 detector at the Fermilab Tevatron…
We present a study to examine the sensitivity of a future $e^{-} e^{+}$ collider to the anomalous top flavour-changing neutral current (FCNC) to the gluon. To separate signal from background a multivariate analysis is performed on top-quark…
We propose a new method for detecting a charged (pseudo-)scalar at colliders, based upon the observation that its Yukawa coupling to charm and bottom quarks can be large due to a significant mixing of the top and charm quarks. After…