119520979
Bounds for lepton flavor violation and the pseudoscalar Higgs boson in the general two Higgs doublet model using the $g-2$ muon factor
Current experimental data from the $g-2$ muon factor, seems to show the necessity of physics beyond the Standard Model (SM), since the difference between SM and experimental predictions is 2.6$\sigma $. In the framework of the General Two Higgs Doublet Model (2HDM), we calculate the muon anomalous magnetic moment to get lower and upper bounds for the Flavour Changing (FC) Yukawa couplings in the leptonic sector. We also obtain lower bounds for the mass of the pseudoscalar Higgs ($m_{A^0}$) as a function of the parameters of the model.
46694686
Light Higgs Boson Production in Two Higgs Doublets Models Type III
By using the Cheng, Sher and Yuan's anzats, we study the light Higgs Boson production associated with b quark production at TEVATRON using the 2HDM type III. We compare the simulations with experimental results coming from TEVATRON, finding valid ranges for the bb coupling. By using these results, we calculate the cross section for the process pp → bbh(bb) for the LHC collider.
119215003
Flavor-changing neutral currents in 331 models
We carry out a general analysis of tree-level flavor-changing neutral currents in the context of 331 models, considering arbitrary quark and gauge boson mixing matrices. The results are applied to definite textures of quark mass matrices, and differences between various 331 scenarios are pointed out.
117937444
Textures of Yukawa coupling matrices in the 2HDM type III
The quark mass matrices ansatze proposed by Fritzsch, Du‐Xing and Fukuyama‐Nishiura in the framework of the general two Higgs doublet model are studied. The corresponding Cabbibo‐Kobayashi‐Maskawa matrix elements are computed in all cases and compared with their experimental values. The complex phases of the anstaze are taken into account and the CP violating phase δ is computed. Finally some phenomenology is discussed.
7716128
Z and Z' decays with and without FCNC in 331 models
In the context of the 331 models, we consider constraints on the extra neutral boson Z{sup '} predicted by the model, where three different quark family assignments are identified. Using the ansatz of Matsuda as an specific texture for the quark mass matrices, we obtain allowed regions associated with the Z-Z{sup '} mixing angle, the mass of the Z{sup '} boson and the parameter {beta} which determines different 331 models. The Z{sub 1} and Z{sub 2} decays with and without flavor changing are also considered. The flavor changing decays of the Z{sub 1} boson into quarks at tree level are highly suppressed by the Z-Z{sup '} mixing angle, obtaining the same order of magnitude as the standard model prediction at one-loop level. The Z{sub 2} decay widths are calculated with and without flavor changing, where oblique radiative corrections at one loop accounts for about 1%-4% deviations.
53625847
Top quark tensor couplings
We compute the real and imaginary parts of the one-loop electroweak contributions to the left and right tensorial anomalous couplings of the tbW vertex in the Standard Model (SM). For both tensorial couplings we find that the real part of the electroweak SM correction is close to 10% of the leading contribution given by the QCD gluon exchange. We also find that the electroweak real and imaginary parts for the anomalous right coupling are almost of the same order of magnitude. The one loop SM prediction for the real part of the left coupling is close to the 3σ discovery limit derived from b → sγ. Besides, taking into account that the predictions of new physics interactions are also at the level of a few percents when compared with the one loop QCD gluon exchange, these electroweak corrections should be taken into account in order to disentangle new physics effects from the standard ones. These anomalous tensorial couplings of the top quark will be investigated at the LHC in the near future where sensitivity to these contributions may be achieved.
119563879
Loop-induced radiative decays of neutral scalars and neutral vector bosons in left-right symmetric theories
Abstract We compute the decay widths of the radiative modes h 0 (H 0 , δ L 0r ) → γγ , γ Z and Z′→ γ h 0 (H 0 , δ L 0r ), where h 0 , H 0 and δ L 0r are the light neutral Higgs scalars of left-right symmetric (LR) models with a minimal Higgs potential. We use a nonlinear R -gauge to compute these one-loop induced decays. We find that only the decay modes which involve the scalar h 0 , the LR analogue of the standard model Higgs boson, are not suppressed by LR mixing angles.
118371403
Phenomenological aspects of the exotic T quark in 331 models
In the context of 331 models we analyze the phenomenology of exotic T quarks with electric charge 2/3. We establish bounds for the corresponding masses and mixing angles and study the decay modes T→bW, tZ and qH. It is found that the decays into scalars are strongly dependent on the model parameters and can be the dominant ones in a scenario with approximate flavor symmetry.