Related papers: Flavour-changing top decays in the aligned two-Hig…
Extension of the SM with one extra Higgs doublet may give rise to flavor-changing-scalar coupling of a neutral Higgs to a pair of top-charm quarks. This coupling gives rise to a large tree-level effective W^+W^-;ZZ - Higgs - t bar-c…
We demonstrate that light charged and extra neutral scalars in the (100-200) GeV mass range pass the potentially dangerous flavor constraints in a particular class of two-Higgs-doublet model which has appropriately suppressed…
We study the decay of a heavy CP-even neutral Higgs into an on-shell Standard Model-like Higgs boson and two photons, $H\to h\gamma\gamma$, in the two-Higgs doublet model. We argue that the decay channel $H\to h\gamma\gamma$, followed by…
We show that the $2.4\sigma$ signal of the leptonic flavor violating (LFV) Higgs boson decay $h\to\mu\tau$, as observed by the CMS collaboration recently, can be explained by a certain class of two-Higgs doublet models that allow…
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…
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…
Searches for light $H^\pm$s via $t\to H^\pm b$ are being carried out at the LHC. Herein, it is normally assumed that the dominant decay channels are $H^\pm\to \tau\nu$ and $H^\pm\to cs$ and separate data analyses are performed with…
The ATLAS Collaboration has recently reported a search for light-charged Higgs in $t\to H^+ b$ decay, with $H^+\to c\bar b$. An excess with a local significance of approximately $3\sigma$ is found at $m_{H^+}\approx130$ GeV, with a best-fit…
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…
With no evidence of any exotic particle detected so far beyond the Standard Model, the new physics may lie above the presently accessible energies at colliders and, at low-energies, can be accounted for via an effective description. The…
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…
The ATLAS and CMS collaborations have recently shown data suggesting the presence of a Higgs boson in the vicinity of 125 GeV. We show that a two-Higgs doublet model spectrum, with the pseudo-scalar state being the lightest, could be…
We perform a detailed study of the exclusive Higgs decays $h\to MZ$ and $h\to MW$, where $M$ is a pseudoscalar or vector meson, using the QCD factorization approach. We allow for the presence of new-physics effects in the form of modified…
A comprehensive phenomenological analysis of a two Higgs doublet model, with flavor changing scalar currents at the tree level, called model III, is presented. Constraints from existing experimental information especially on (Delta F)=2…
The possibility of detecting double flavor violating top quark transitions at future colliders is explored in a model-independent manner using the effective Lagrangian approach through the $t \to u_i\tau \mu$ ($u_i=u,c$) decays. A Yukawa…
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,…
The invisible variant axion model is very attractive as it is free from the domain wall problem. This model requires two Higgs doublets at the electroweak scale where one Higgs doublet carries a nonzero Peccei-Quinn (PQ) charge and the…
The Two Higgs Doublet model and its phenomenological implications are discussed. A brief survey on the present status of this model is given. In particular, we concentrate on the Two Higgs Doublet Model with Flavor Changing Neutral…
The data accumulated so far confirm the Higgs-like nature of the new boson discovered at the LHC. The Standard Model Higgs hypothesis is compatible with the collider results and no significant deviations from the Standard Model have been…
We calculate loop induced lepton flavor violating Higgs decays in the Littlest Higgs model with T-parity. We find that a finite amplitude is obtained only when all contributions from the T-odd lepton sector are included. This is in contrast…