相关论文: Physical constraints derived from FCNC in the 3-3-…

The significance of new physics appearing in the loop-induced decays of neutral Higgs bosons into pairs of dibosons $\gamma\gamma$ and $Z\gamma$ will be discussed in the framework of the 3-3-1 models based on a recent…

Extensions of the standard model (SM) with gauge symmetry SU(3)_c X SU(4)_L X U(1)_X (3-4-1 extensions) where anomaly cancellation takes place between the fermion families (three-family models) predict the existence of two new heavy neutral…

Flavor-changing neutral current (FCNC) processes play a prominent role in the search for physics beyond the Standard Model (SM) due to their sensitivity to new physics at the TeV scale. Meson-antimeson transitions and rare meson decays…

We study phenomenological constraints on a simple $3-3-1$ model with flavor violating Yukawa couplings. Both triplets Higgs couple to leptons and quarks, which generates flavor violating signals in both lepton and quark sectors. We have…

The B_s to mu+ mu- decay plays an outstanding role in tests of the Standard Model and physics beyond it. The LHCb collaboration has recently reported the first evidence for this decay at the 3.5 sigma level, with a branching ratio in the…

We study constraints and implications of the recent LHCb measurement of ${\cal B}(B_s \to \mu^+\mu^-)$ for tree-level Higgs-mediated flavor-changing neutral current (FCNC) interactions. Combined with experimental data on $B_s$ mass…

We analyse the constraints and some of the phenomenological implications of a class of two Higgs doublet models where there are flavour-changing neutral currents (FCNC) at tree level but the potentially dangerous FCNC couplings are…

The recent precision measurement of the $W$-boson mass reveals an exciting hint for the new physics as of the 3-3-1 model. We indicate that the 3-3-1 model contains distinct sources by itself that may cause the $W$-mass deviation, as…

Recent experimental results on exclusive semi-tauonic B meson decays show sizable deviations from the standard model prediction, while the recent result on pure-tauonic decay reduces the deviation from the prediction. These results suggest…

In this work, we update the constraints on tree level FCNC couplings in the framework of a theory with n isosinglet vector-like down quarks. In this context, we emphasize the sensitivity of the B -> J/psi K_S CP asymmetry to the presence of…

We consider the Higgs boson anomalous FCNC interactions with $u$, $c$, $d$, $s$ and $b$ quarks using the effective field theory framework. Constraints on anomalous couplings are derived from experimental results on Higgs boson production…

We revise the limits on the FCNC higgses in manifestly left-right symmetric theories. It is shown that the combination of the Kobayashi-Maskawa CP-violation with the tree level $\Delta S=2$ higgs exchange gives very large contribution to…

We investigate, in detail, a model in which the third family fermions are subjected to an SU(2) dynamics different from the first two families. Constrained by the precision Z-pole data, the heavy gauge boson mass is bounded from below to be…

Measuring the Higgs couplings accurately at colliders is one of the best routes for finding physics Beyond the Standard Model (BSM). If the measured couplings deviate from the SM predictions, then this would give rise to energy-growing…

Sources of Flavor Changed Neutral Currents (FCNC) naturally emerge from a well motivated framework called 3-3-1 with right-handed neutrinos model, $331_{RHN}$ for short, mediated by an extra neutral gauge boson $Z^{\prime}$. Following…

Flavour-Changing-Neutral-Currents (FCNC) play an important r\^ ole in testing the Standard Model (SM) while probing the possibility of having New Physics beyond the SM. In the SM, FCNC are forbidden at three level, but arise through…

We analyse a class of two Higgs doublet models where flavour-changing neutral currents (FCNC) are present at tree level in a mixing-suppressed manner. In this class of models, because of a discrete symmetry imposed on the lagrangian, the…

In recent times, several discrepancies at the level of $(2-3)\sigma$ have been observed in the decay processes mediated by flavour changing neutral current (FCNC) transitions $b \to s \ell^+ \ell^-$, which may be considered as the…

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…

We examine extensions of the MSSM with more than one generation of Higgs bosons. If one assumes that a symmetry eliminates the tree-level FCNC, then the extra scalar bosons do not acquire VEVs, do not couple to fermions and do not mix with…