Related papers: Flavor-Changing Neutral-Current Decays in Top-Spec…
This article presents a search for flavour-changing neutral currents in the decay of a top quark into an up-type ($q = c, u$) quark and a Higgs boson, where the Higgs boson decays into two photons. The proton--proton collision data set…
We propose an efficient mechanism to realize an invisible axion from a low scale Peccei-Quinn symmetry breaking. Our basic model only contains a gauge boson, an up-type vector-like quark, two Higgs doublets and two Higgs singlets besides…
Top quark physics at the LHC may open a window to physics beyond the standard model and even lead us to an understanding of the phenomenon "flavour". However, current flavour data is a strong hint that no "new physics" with a generic…
The flavor changing neutral top quark decay t -> c X is computed, where X is a neutral standard model particle, in a extended model with a single extra dimension. The cases for the photon, X= \gamma$, and a Standard Model Higgs boson, X =…
Flavor violating interactions of the Higgs boson are a generic feature of models with extended electroweak symmetry breaking sectors. Here, we investigate CP violation in these interactions, which can arise from interference of tree-level…
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…
If $t\rightarrow hq$ ($q=c,u$) or $h\rightarrow\tau\ell$ ($\ell=\mu,e$) decays are observed, it will be a clear signal of new physics. We investigate whether natural and viable flavor models can saturate the present direct upper bounds…
In a general two Higgs doublet model, we study flavor changing neutral Higgs (FCNH) decays into leptons at hadron colliders, $pp \to \phi^0 \to \tau^\mp\mu^\pm +X$, where $\phi^0$ could be a CP-even scalar ($h^0$, $H^0$) or a CP-odd…
We study lepton flavor violating Higgs decays in two models, with the recently found hint for Higgs $\to \mu \tau$ at CMS as a benchmark value for the branching ratio. The first model uses the discrete flavor symmetry group $A_4$, broken at…
In this Thesis we have investigated some effects appearing in top quark and Higgs boson decays with flavor changing neutral currents (FCNC) in the framework of generic Two Higgs Doblet Models (2HDM) and the Minimal Supersymmetric Standard…
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…
We analyze the prospects for observing the CP-even neutral Higgs bosons (h and H) in their decays into flavor violating $b \bar s+ c.c.$ channels at the proposed LHeC, with $\sqrt s \approx 1.3$ TeV, in the 2HDM Type-III, assuming a…
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…
The invisible variant axion models (VAM's) offer a very attractive solution for the strong CP problem without the domain wall problem. We consider the up-type specific variant axion models and examine their compatibility with the muon $g-2$…
We study the flavor-changing couplings of the Higgs-boson with the top-quark using the processes: (a) pp --> tt, (b) pp --> t_bar j, and, (c) pp --> t_bar j h at the LHC in light of current discovery of a 126 GeV Higgs-Boson. Sensitivities…
We study a class of DFSZ-like models for the QCD axion that can address observed anomalies in stellar cooling. Stringent constraints from SN1987A and neutron stars are avoided by suppressed couplings to nucleons, while axion couplings to…
In Two Higgs doublet extensions of the Standard Model, flavor-changing neutral current constraints can be addressed by introducing a U(1)' gauge symmetry, under which the Higgs doublets carry different charges. That scenario implies the…
The phenomenology of a charged Higgs present in a model with two Higgs SU(2) doublets and a $Z_3$ flavor symmetry is analyzed. It is shown that it is possible to generate an enhancement of its flavor changing coupling to c and b quarks and…
We analyze the prospect for observing the lightest and heaviest CP-even neutral Higgs bosons ($\phi=h,\;H$) in their decays to flavor violating $b\bar{s}$ (with charge conjugate) final states at the future Large Hadron electron Collider…
We study the decay width, forward-backward asymmetry and the longitudinal lepton polarization for the exclusive decay B --> K^* l^+ l^- in the two Higgs doublet model with three level flavor changing neutral currents (model III) and analyse…