Related papers: Flavor changing neutral currents in 331 models
Low-energy experiments involving kaon, B-meson, D-meson, and hyperon flavor-changing neutral transitions have confirmed the loop-induced flavor-changing neutral current (FCNC) picture of the standard model (SM). The continuing study of…
We study the flavor changing neutral current couplings of new heavy quarks through the Z' models at the LHC. We calculate the cross sections for the signal and the corresponding standard model background processes. Considering the present…
The possibility of adding an SU(2) horizontal symmetry to the 331 model is studied. It is found that simple, anomaly-free fermion assignments can be made which lead to plausible results for fermion masses and mixings. In particular, all…
A systematic study of the flavor group $T^{'}$ is presented in terms of a specific model which extends the standard model symmetry to $[SU(3) \times SU(2) \times U(1)]_{(local)} \times [T^{'} \times Z_2 \times Z_2^{'} \times…
We numerically study the zero temperature phase structure of the multiflavor Schwinger model at nonzero chemical potential. Using matrix product states, we reproduce analytical results for the phase structure for two flavors in the massless…
We point out that the stringent lower bounds on the masses of additional electrically neutral and charged Higgs bosons crucially depend on the flavour structure of their Yukawa interactions. We show that these bounds can easily be evaded by…
New class of models are constructed in which the third family quarks, but not leptons, experience a new SU(2) or U(1) gauge force. Anomaly cancellation enforces the introduction of spectator quarks so that the top and bottom masses are…
An exact calculation of the Higgs boson decays $H\to q_i q_j$ mediated by flavor changing neutral currents is presented in the context of the Standard Model. Using up-to-date experimental data, branching ratios of the order of $10^{-7}$,…
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…
Inspired by the recent Georgi's unparticle proposal, we study the flavor structures of the standard model (SM) particles when they couple to unparticles. At a very high energy scale, we introduce $\BZ$ charges for the SM particles, which…
We show how a novel fine-tuning problem present in the Standard Model can be solved through the introduction of a single flavour symmetry G, together with three $Q = - 1/3$ quarks, three $Q = 2/3$ quarks, as well as a complex singlet…
A multiflavor model for dynamical chiral breaking reveals a solution highly suitable for stimulation of flavor mass hierarchy and mixings. The mechanism triggering the both phenomena simultaneously suppresses flavor changings. Thus, the…
We study the effect of -mediated flavor-changing neutral current on the decays. The branching ratios of these decays can be enhanced remarkably in the non-universal model. Our estimated branching ratios are enhanced significantly from their…
The standard model extended with the pairs of the vector-like families is studied. The model independent analysis for an arbitrary case and an explicit realization for the case with one pair of the heavy vector-like families are considered.…
The Flavor Changing Neutral Current decays(FCNC) is forbidden at tree level in the Standard Model (SM) and could only contribute through loops. Any direct observation beyond SM expectations could be a good probe of physics beyond SM. BESIII…
Numerical correlations between fermion masses and mixings could indicate the presence of a flavor symmetry at high energies. In general, the search for these correlations using low-energy data requires an estimate of leading-log radiative…
We discuss the phase diagram of moderately dense, locally neutral three-flavor quark matter using the framework of an effective model of quantum chromodynamics with a local interaction. The phase diagrams in the plane of temperature and…
Flavour changing neutral scalar interactions are a standard feature of generic multi Higgs models. These are constrained by mixing in the neutral meson systems. We consider situations where there are natural cancellations in such…
The flavor changing neutral current decays $t\to c X$ ($X=\gamma,\,g,\, Z,\, H$) and $t\to c\bar \ell\ell $ ($\ell=\mu,\,\tau$) are studied in a renormalizable scalar leptoquark (LQ) model with no proton decay, where a scalar $SU(2)$…
For a long time, investigation into the weak interactions of quarks has guided us toward understanding the Standard Model we know today. Now in the era of high precision, these studies are still one of the most promising avenues for peering…