No Arabic abstract
We show that in the minimal 3-3-1 model the flavor changing neutral currents (FCNCs) do not impose necessarily strong constraints on the mass of the $Z^prime$ of the model if we also consider the neutral scalar contributions to such processes, like the neutral mesons mass difference and rare semileptonic decays. We first obtain numerical values for all the mixing matrices of the model i.e., the unitary matrices that rotate the left- and right-handed quarks in each charge sector which give the correct mass of all the quarks and the CKM mixing matrix. Then, we find that there is a range of parameters in which the neutral scalar contributions to these processes may interfere with those of the $Z^prime$, implying this vector boson may be lighter than it has been thought.
We show that the economical 3-3-1 model poses a very high new physics scale of the order of 1000~TeV due to the constraint on the flavor-changing neutral current. The implications of the model for neutrino masses, inflation, leptogenesis, and superheavy dark matter are newly recognized. Alternatively, we modify the model by rearranging the third quark generation differently from the first two quark generations, as well as changing the scalar sector. The resultant model now predicts a consistent new physics at TeV scale unlike the previous case and may be fully probed at the current colliders. Particularly, due to the minimal particle contents, the models under consideration manifestly accommodate dark matter candidates and neutrino masses, with novel and distinct production mechanisms. The large flavor-changing neutral currents that come from the ordinary and exotic quark mixings can be avoided due to the approximate $B-L$ symmetry.
In this paper we present the mass matrices and mass eigenstates for the CP-even neutral scalars in the minimal 331 model (m331) and its self-interactions, showing that the m331 automatically reproduces the Higgs potential of the Standard Model. We also present a method to generate numerical solutions for the quarks and leptons masses and their mixings, which we apply to study FCNC processes, being to calculate the contributions of all exotic neutral particles of the m331 to the mass differences in meson oscillations.
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 shown that this model can allow for large Higgs lepton flavor-violating rate decay $h rightarrow mu tau$ and also can be reached to perfect agreements with other experimental constraints such as $tau rightarrow mu gamma$ and $(g-2)_mu$. The contributions of flavor-changing neutral current (FCNC) couplings, Higgs-quark-quark couplings, to the mesons mixing are investigated. Br$(h rightarrow q q^prime )$ can be enhanced with keeping from the measurements of meson mixing. The branching ratio for $t rightarrow q h$ can reach up to $10^{-3}$, but it could be as low as $10^{-8}$.
In the minimal 3-3-1 model charged leptons come in a non-diagonal basis. Moreover the Yukawa interactions of the model lead to a non-hermitian charged lepton mass matrix. In other words, the minimal 3-3-1 model presents a very complex lepton mixing. In view of this we check rigorously if the possible textures of the lepton mass matrices allowed by the minimal 3-3-1 model can lead or not to the neutrino mixing required by the recent experiments in neutrino oscillation.
We calculate the electric dipole moment (EDM) for the neutron in the framework of the minimal 3-3-1 model. We assume that the only source of $CP$ violation arises from a complex trilinear coupling constant and two complex vacuum expectation values. However, from the constraint equations obtained from the potential, only one physical phase remains. We find some constraints on the possible values of this phase and masses of the exotic particles.