Related papers: The GIM Mechanism: origin, predictions and recent …
Processes involving flavor changing neutral currents (FCNC) provide excellent signatures with which to search for evidence of new physics. They have very small branching fractions in the Standard Model since they are highly suppressed by…
We study the Glashow-Iliopoulos-Maiani mechanism for flavor-changing-neutral-currents suppression in both, the gauge and Higgs sectors, for models with $SU(3)_L\otimes U(1)_N$ gauge symmetry. The models differ one from the other only with…
In a simple extension of the standard electroweak theory where the phenomenon of lepton flavor mixing is described by a 3x3 unitary matrix V, the electric and magnetic dipole moments of three active neutrinos are suppressed not only by…
We consider the phenomenology of a composite technicolor model proposed recently by Georgi. Composite technicolor interactions produce four-quark operators in the low energy theory that contribute to flavor changing neutral current…
We explore how to protect extra dimensional models from large flavor changing neutral currents by using bulk and brane flavor symmetries. We show that a GIM mechanism can be built in to warped space models such as Randall-Sundrum or…
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…
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…
The three theoretical and historical components of the Standard Model are the exact chiral gauge theory of weak interactions, electroweak unification, and the Higgs mechanism for spontaneous symmetry breaking. I put into historical…
The Dualized Standard Model which gives explanations for both fermion generations and Higgs fields has already been used to calculate fermion mass and mixing parameters with success. In this paper, we extend its application to low energy…
We review the theory and experimental measurements in the flavour changing neutral current (FCNC) processes involving B decays in the context of the standard model (SM). The role of these processes in determining the weak mixing matrix…
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…
Constraints from flavour changing neutral currents are discussed in the context of predictive Grand Unified Supersymmetric Theories. Uncertainties in the estimation of their amplitudes are minimized by using a successful mass matrix ansatz…
We present a summary of our recent analysis update of flavour changing neutral current (FCNC) processes in the Littlest Higgs model with T-parity (LHT). The essential novelties of our update are: the removal of the logarithmic UV cutoff…
We consider supersymmetric extensions of the standard model with general non-universal soft breaking terms. We analyse in a model-independent way the constraints on these terms at the electroweak energy scale coming from gluino mediated…
We propose the local $(B-L)_{\mu\tau}$ model, which minimally retains the local $B-L$ extension for the sake of neutrino phenomenologies, and at the same time presents an invisible gauge boson $Z'$ with mass $\sim {\cal O}(10)$ MeV to…
The Cabibbo-Kobayashi-Maskawa (CKM) mixing matrix and flavor-changing neutral currents (FCNC's) in the quark sector are examined in the GUT inspired $SO(5) \times U(1) \times SU(3)$ gauge-Higgs unification in which the 4D Higgs boson is…
We review the status of the flavour-changing neutral-current processes (FCNC). In particular we discuss: i) Main targets of the field, ii) The theoretical framework for FCNC, iii) Standard analysis of the unitarity triangle, iv)…
In the Standard Model (SM), flavour changing neutral current (FCNC) top decays, possible at loop level only, are very strongly suppressed. Observation of any such decay would be a direct signature of physics beyond the SM. Large…
Flavor changing neutral currents (FCNCs) in the charm system are highly suppressed in the standard model (SM). The theoretical strategies used to suppress FCNCs induced by supersymmetry in the strange and beauty systems need not apply to…
The standard model prediction for a magnetic dipole moment of a neutrino is proportional to the neutrino mass and extremely small. It also generates a flavor-changing process, but the GIM mechanism reduces the corresponding amplitude. These…