arXiv subjects

J. -Alexis Rodriguez

Publications and source records attributed to J. -Alexis Rodriguez.

23 records · Page 2Linked to original sources

arXiv2001

Bounds for Lepton Flavor Violation and the Pseudoscalar Higgs in the General Two Higgs Doublet Model using $g-2$ 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$σ$. 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.

hep-ph↗

arXiv2000

Lepton Flavor Violation in the Two Higgs Doublet Model type III

We consider the Two Higgs Doublet Model (2HDM) of type III which leads to Flavour Changing Neutral Currents (FCNC) at tree level in the leptonic sector. In the framework of this model we can have, in principle, two situations: the case (a) when both doublets acquire a vacuum expectation value different from zero and the case (b) when only one of them is not zero. In addition, we show that we can make two types of rotations for the flavor mixing matrices which generates four types of lagrangians, with the rotation of type I we recover the case (b) from the case (a) in the limit $\tan β\to \infty $, and with the rotation of type II we obtain the case (b) from (a) in the limit $\tan β\to 0. $Moreover, two of the four possible lagrangians correspond to the models of types I and II plus Flavor Changing (FC) interactions. The analitical expressions of the partial lepton number violating widths $Γ(μ\to eee) $ and $Γ(μ\to eγ) $are derived for the cases (a) and (b) and both types of rotations.$ $In all cases these widths go asymptotically to zero in the decoupling limit for all Higgses. We present from our analysis upper bounds for the flavour changing transition $μ\to e,$ and we show that such bounds are sensitive to the VEV structure and the type of rotation utilized.

hep-ph↗

arXiv2000

The H -> gamma gamma in Multi-Higgs doublet models

We study the dominant decays of the lightest Higgs boson in models with 2 and 3 Higgs doublets, for the case when its couplings to fermions are absent at tree-level. It is found that the branching ratio for the decay $H\to γγ$ is above the one into fermion pairs, which is evaluated also at the 1-loop level.

hep-ph↗

arXiv1998

Compositeness and the asymmetries of leptons at the Z^0 peak

We study the effects on the leptonic asymmetries A_{FB}, A_{pol} and A_{LR} coming from a model of compositeness. We consider the effects coming from the self-energies and the vertex correction to $Z l^+ l^-$. Thus we use the Altarelli parametrization of the oblique corrections. We get the asymptotic limits of these corrections in terms of the parameters $(m^*, Λ, f, f')$ and we get bounds for the quotient $m^*/Λ$ with different values of $(f, f')$. We conclude that both asymmetries produce bounds for such quotient when $f'$ overweigth to $f$, and this fact is related with the breakdown of the custodial symmetry.

hep-ph↗

arXiv1997

The Anomalous Chromomagnetic Dipole Moment of the Top Quark

We calculate the one loop corrections to the chromomagnetic dipole moment of the top quark in the framework of the Standard Model, the two Higgs doublet model and the Minimal Supersymmetric Standard Model. In the Standard Model we consider the QCD and the electroweak corrections generated by gluon and Higgs boson exchanges, respectively. In the Minimal Supersymmetric Standard Model, we calculate the SUSY- QCD corrections, including the mixing effects between the stop coming from the left- and right-handed sectors. We obtain that the Standard Model contribution is of the order of -0.004< delta kappa_g^t < -0.001, and the values for diferents scenarios are of the order of -0.001 < δκ_g^t < -0.01.

hep-ph↗