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.
118490669
Production of multiple charged Higgs bosons in 3-3-1 models
We undertake the study of the charged Higgs bosons predicted by the model with gauge symmetry SU(3)c ⊗SU(3)L ⊗U(1)X. By considering Yukawa mixing couplings between small (∼ GeV) and large (∼ TeV) scales, we show that the hypercharge-one H ± 1 and hypercharge-two H ± 2 Higgs bosons predicted by the model, can be simultaneously produced in pp collisions at different production rates. At low energy, the H ± 1 bosons exhibit the same properties as the charged Higgs bosons from a two Higgs doublet model (2HDM), while H ± 2 are additional like-charged Higgs bosons from the underlying 3-3-1 model. Thus, the identification of multiple like-charged Higgs boson resonances may test the compatibility of theoretical models with experimental data. We study H ±
124873913
$B \to$ X($s \gamma^{)}$ and $B^{+} \to \ell^{+} \nu$ in the 2 HDM type III
122784148
Anomalous top magnetic couplings
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) are computed.
14151824
Different kind of textures of Yukawa coupling matrices in the two Higgs doublet model type III
The quark mass matrices ansätze proposed by Fritzsch, Du–Xing and Fukuyama–Nishiura in the framework of the general two Higgs doublet model are studied. The corresponding Yukawa matrices in the flavor basis in the various cases considered are discussed. The corresponding Cabibbo–Kobayashi–Maskawa matrix elements are computed in all cases and compared with their experimental values. The complex phases of the ansätze are taken into account, and the CP violating phase δ is computed. Finally, in order to observe the influence of the various kinds of texture of the Yukawa coupling matrices considered, some issues in the phenomenology of the two body decays of the top quark, the lightest Higgs boson and the charged Higgs boson are discussed.
119271341
Quark mass hierarchy in 3-3-1 models
We study the mass spectrum of the quark sector in an special type I-like model with gauge symmetry $SU(3)_c \otimes SU(3)_L \otimes U(1)_X$. By considering couplings with scalar triplets at large ($\sim TeV$) and small ($\sim GeV$) scales, we obtain specific zero-texture mass matrices for the quarks which predict three massless quarks ($u,d,s$) and three massive quarks ($c,b,t$) at the electroweak scale ($\sim$ GeV). Taking into account mixing couplings with three heavy quarks at large scales predicted by the model, the three massless quarks obtain masses at small order that depends on the inverse of the large scale. Thus, masses of the form $m_u \lesssim m_d < m_s \sim MeV$ and $ m_{c,b,t} \sim GeV$ can be obtained naturally from the gauge structure of the model.
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.