Related papers: Self-cancelation of a scalar in neutral meson mixi…
We discuss a model, in which the negative mass square needed in the Higgs mechanism is generated by mixing with a heavy scalar. We have two scalar doublets in the standard model. Phenomenological properties of the heavy new scalar are…
We consider an extension of the Standard Model in which the symmetry is enlarged by a global flavour factor A4 and the scalar sector accounts for three copies of the Standard Model Higgs, transforming as a triplet of A4. In this context, we…
Flavour changing neutral current processes, being strongly suppressed in the Standard Model (SM), provide a unique window to new physics at scales much above the electroweak scale. Here, we summarize the recent progress in flavour physics…
We study flavour-changing neutral current decays of the top quark in the democratic Three Higgs Doublet Model featuring a $Z_3$-symmetric scalar potential and Natural Flavour Conservation. In this framework, while such processes are absent…
Meson and anti-meson mixing processes constitute an important source of constraints on models that give tree level contributions to flavor violating neutral processes. In electroweak $ \text{SU}(3)_\text{L} \times \text{U}(1)_N $ models,…
We analyse scalar flavour-changing neutral currents of down-type quarks in models with two Higgs doublets, coupled separately to up- and down-type quarks, in the limit where the ratio of the two expectation values ($\tan \beta = v_u/v_d$)…
The Standard Model (SM), when extended with a leptoquark (LQ) and right-handed neutrinos, can have interesting new implications for Higgs physics. We show that sterile neutrinos can induce a boost to the down-type quark Yukawa interactions…
In extended Higgs models, a discrete symmetry is needed in the quark sector to avoid tree-level flavor-changing neutral currents. However, this is not necessary the case in the lepton sector. We consider a model in which one Higgs couples…
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…
New singlet scalar bosons have broad phenomenological utility and feature prominently in many extensions of the Standard Model. Such scalars are often taken to have Higgs-like couplings to SM fermions in order to evade stringent flavor…
In this work, we propose and explore for the first time a new collider signature of heavy neutral scalars typically found in many distinct classes of multi-Higgs models. This signature, particular relevant in the context of the Large Hadron…
We analyse various flavour changing processes like $t\to hu,hc$, $h\to \tau e,\tau\mu$ as well as hadronic decays $h\to bs,bd$, in the framework of a class of two Higgs doublet models where there are flavour changing neutral scalar currents…
A plethora of ultraviolet completions of the Standard Model have extra U(1) gauge symmetries. In general, the associated massive $Z^\prime$ gauge boson can mediate flavor-changing neutral current processes at tree level. We consider a…
New physics scenarios beyond the Standard Model (SM) for neutrino mass mechanism often necessitate the existence of a neutral scalar $H$ and/or doubly-charged scalar $H^{\pm\pm}$, which couple to the SM charged leptons in a flavor violating…
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…
The mass matrix forms of quarks and leptons are discussed in theory with permutation flavor symmetry. The structure of scalar potential is analyzed in case that electroweak doublet Higgs fields have non-trivial flavor symmetry charges. We…
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…
We investigate the potential of the HL-LHC for discovering new physics effects via the same-sign top pair signatures. We focus on the semi leptonic (electron and muon) decay of the top quarks and study the reach for a simplified model…
In 3-3-1 models anomaly cancellation requires that one of the three families of quarks transforms as triplet by $\text{SU}(3)_\text{L}$ with the other two transforming necessarily as anti-triplet. This is an important feature of the model…
To study a flavour model with a non-minimal Higgs sector one must first define the symmetries of the fields; then identify what types of vacua exist and how they may break the symmetries; and finally determine whether the remnant symmetries…