arXiv subjects

J. -Alexis Rodriguez

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

At least 19 recordsLinked to original sources

arXiv2013

Charged lepton mixing processes in 331 Models

Processes $τ\rightarrow lγ$, $τ\rightarrow lll$ with $l= e,μ$ and $μ(τ) \to e (μ) γ$ are evaluated in the framework of a model based on the extended symmetry gauge $SU(3)_c \otimes SU(3)_L \otimes U(1)_Y$ with a leptonic sector consistent of five triplets. Lepton flavor violating processes are allowed at tree level in this model through the new $Z'$ gauge boson. We obtained bounds for the mixing angles in the leptonic sector of the model, considering the experimental measurements of the processes from the BELLE and the BABAR collaborations.

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arXiv2013

Lepton Flavor Violation processes in 331 Models

Models based on the extended symmetry gauge $SU(3)_c \otimes SU(3)_L \otimes U(1)_Y$ can be build up with a leptonic sector consistent of five triplets in different $SU(3)_L$ representations where additional heavy fermions are included. Some of these models present flavor changing neutral currents in the leptonic sector which are mediated through the $Z'$ boson. One of these models is studied using the measurements of lepton flavor violation processes such as $τ\rightarrow lll$ with $l= e,μ$ and $μ(τ) \to e (μ) γ$.

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arXiv2013

Electric charge quantization in SU(3)XSU(4)XU(1) models

We obtain electric charge quantization in the context of models based on the gauge symmetry group SU(3) X SU(4) X U(1). The gauge models studied include three families to cancel out anomalies and a set of scalar fields to break spontaneously the symmetry. To show the electric charge quantization, we use clasical symmetry conditions and quantum quiral anomaly conditions.

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arXiv2012

The Higgs decay rate to two photons in a model with two fermiophobic-Higgs doublets

We consider a three Higgs doublet model with an $S_3$ symmetry in which beside the SM-like doublet there are two fermiophobic doublets. Due to the new charged scalars there is an enhancement in the two-photon decay while the other channels have the same decay widths that the SM neutral Higgs. The fermiophobic scalars are mass degenerated unless soft terms breaking the $S_3$ symmetry are added.

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arXiv2012

The role of charged Higgs boson decays in the determination of tanβ-like parameters

The most commonly used parameterizations of the Yukawa couplings in the two Higgs doublet model are revisited. Their similitudes and differences are emphasized and relations between the different notations used in the literature are derived. Using these relations, bounds on the space of parameters of the charged Higgs sector of the two Higgs doublet model are obtained. These constraints are obtained from flavor observables like the measurement of B -> Xs γand the recent measurement of Bs -> μ+ μ- from LHCb. The ratio R_{H+}=B(H+ -> τ^+ ν_τ)/B(H+ -> t b) is evaluated for the two Higgs doublet model type-III and type-II, and their differences are quantified.

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arXiv2011

Constraints on the charged Higgs boson of the two Higgs doublet model type III

The D0 experiment has reported a direct search for a charged Higgs boson produced by $q \bar q$ annihilation and decaying to $t \bar b$ final state, in the $180 \leq M_{H^+} \leq 300$ GeV mass range. The analysis has lead to upper limits on the production cross section in the framework of the two Higgs doublet model types I, II and III. We compare the predictions of two different scenarios in the framework of the two Higgs doublet type III to the cross section limits reported by D0 collaboration, and we obtain constraints on the charged Higgs mass, for the case when the charged Higgs mass is bigger than the top quark mass. Also, searches for the charged Higgs boson with a mass smaller than top quark mass are considered, we discuss the possible limits on the charged Higgs boson mass obtained from measurements of the ratio $R_σ=σ_{t \bar t}^{l+jets}/σ_{t \bar t}^{dileptons}$ within the two Higgs doublet model type III.

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arXiv2008

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 $pp \to b\bar bh(b\bar b)$ for the LHC collider.

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arXiv2008

Charged Higgs production at photon colliders in 2HDM-III

We study charged Higgs production in the process $γγ\to A^0\to W^- H^+$. The processes $γγ\to A^0$ are loop mediated in a 2HDM. This is due to the fact that photons only couple directly to charged particles and the Higgs only couples to particles with mass acquired via Higgs mechanism. Although in MSSM the contribution from the process $γγ\to A^0$ is too small, it has been found that in a more general 2HDM it could be enhanced. On the other hand, the boson $A^0$ can decay in $W^- H^+$ at tree level and the charged Higgs can decay in fermions. So, the whole process under study is $γγ\to A^0\to (W^-\to lν) (H^+\to f_if_j)$ in 2HDM-III. Evidence about charged Higgs existence could demonstrate that structure of the Higgs sector has several multiplets.

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arXiv2007

FCNC Top Quark Decays in Extra Dimensions

The flavor changing neutral top quark decay t -> c X is computed, where X is a neutral standard model particle, in a extended model with a single extra dimension. The cases for the photon, X= γ$, and a Standard Model Higgs boson, X = H, are analyzed in detail in a non-linear$R_ξgauge. We find that the branching ratios can be enhanced by the dynamics originated in the extra dimension. In the limit where 1/R >> ->, we have found Br(t -> c γ) \simeq 10^{-10} for 1/R = 0.5 TeV. For the decay t -> c H, we have found Br(t -> cH) \simeq 10^{-10} for a low Higgs mass value. The branching ratios go to zero when 1/R -> \infty.

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arXiv2007

Different kind of textures of Yukawa coupling matrices in the two Higgs doublet model 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 Yukawa matrices in the flavor basis in the different cases considered are discussed. The corresponding Cabbibo-Kobayashi-Maskawa matrix elements are computed in all cases and compared with their experimental values. The complex phases of the ansatze are taken into account and the CP violating phase $δ$ is computed. Finally, in order to observe the influence of the different kind of textures of Yukawa coupling matrices considered, some phenomenology of two body decays of the top quark, the lightest Higgs boson and the charged Higgs boson is discussed.

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arXiv2005

The lightest Higgs boson production at photon colliders in the 2HDM-III

The branching ratios of the lightest CP-even Higgs boson $h^0$, in the framework of the General Two Higgs Doublet Model are calculated. Different scenarios are presented taking into account constraints obtained in previous works on the flavor changing neutral currents factors. Plausible scenarios with flavour changing processes at tree level like $b \bar s$ and $t \bar c$ are analyzed for relevant region of parameters. The loop-induced Higgs couplings to photon pairs can be tested with a photon collider. The number of events of $h^0$ as a resonance in photon colliders are calculated taking into account its corresponding background signal in TESLA, CLIC and NLC.

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arXiv2004

FCNC and Rare B Decays in 3-3-1 Models

An interesting extension of the Standard Model is based on the electroweak gauge group SU(3)_L x U(1). It requires three generations to cancel anomalies, treats the third generation differently than the first two, and has a rich phenomenology. There are several models, distinguished by the embedding of the charge operator into the SU(3)_L group and by the choice of fermion representations. In this Brief Report, we consider flavor-changing neutral currents in these models, concentrating on the P-Pbar mass difference, where P=(K, D, B, B_s), as well as B --> K l^+ l^-, B --> mu^+ mu^- and B_s --> mu^+ mu^- decays. Although the P-Pbar mass difference has been considered previously in some models, the rare B decays are new. We find that the strongest bounds come from the B-Bbar and Bs-Bs-bar mass differences.

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arXiv2004

Higgs boson decays in the littlest Higss model

We calculate the two body Higgs boson decays in the framework of the littlest Higgs model. The decay $H \to γZ$ is computed at one loop level and, using previous results, we evaluate the branching fractions in the framework of the littlest Higgs model. A wide range of the space parameter of the model is considered and possible deviations from the standard model are explored.

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arXiv2004

The upper bound of the lightest Higgs boson in a supersymmetric $SU(3)_L \otimes U(1)_X$ gauge model

A supersymmetric version of the $SU(3)_L \otimes U(1)_X$ gauge model is presented. The model is embedded in a $SU(6)_L \otimes U(1)_X$ gauge group and it has been built up completely quiral anomaly free and without any exotic charges in the fermionic content. The Minimal Supersymmetric Standard Model can be seen as an effective theory of this larger symmetry. We analyze how the spectrum of the new model can shift the upper bound on the CP-even Higgs boson and we find that it can be moved up to 143 GeV.

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arXiv2003

Bounds on charged higgs boson in the 2HDM type III from Tevatron

We consider the Two Higgs Doublet Model (2HDM) of type III which leads to Flavour Changing Neutral Currents (FCNC) at tree level. In the framework of this model we can use an appropriate form of the Yukawa Lagrangian that makes the type II model limit of the general type III couplings apparent. This way is useful in order to compare with the experimental data which is model dependent. The analytical expressions of the partial width $Γ(t \to H^+ b) $ are derived and we compare with the data available at this energy range. We examine the limits on the new parameters $λ_{ij}$ from the validness of perturbation theory.

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arXiv2003

Effective theories and constraints on new phyhsics

Anomalous moments of the top quark arises from one loop corrections to the vertices $\bar t t g$ and $\bar t t γ$. We study these anomalous couplings in different frameworks: effective theories, Standard Model and 2HDM. We use available experimental results in order to get bounds on these anomalous couplings.

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arXiv2002

Phenomenology of lepton flavor violation in 2HDM(III) from (g-2)_mu and leptonic decays

We constrain some lepton flavor violating vertices in the context of the two Higgs doublet model type III, assuming that the lightest scalar Higgs mass $% m_{h^{0}} $is about $115 $GeV. Specifically, based on the $g-2 $muon factor and the decay width of$ μ\to eγ$,$ $the following quite general bounds are obtained:$ 7.62\times 10^{-4}\lesssim ξ_{μτ}^{2}\lesssim 4.44\times 10^{-2}, $ $ξ_{eτ}^{2}\lesssim 2.77\times 10^{-14}$. Additionally, based on the processes $τ\to μγ$, and $τ\to μμμ$, bounds on $ξ_{ττ} $and $ξ_{μμ} $are also gotten, such constraints on these parameters$ $still give enough room for either a strong suppression$ $or strong enhancement on the coupling of any Higgs boson to a pair of tau leptons or a pair of muons\textbf{.} Furthermore, upper limits on the decay widths of the leptonic decays $τ\to eγ, $and $τ\to eee $are calculated, finding them to stay far from the reach of near future experiments.

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arXiv2001

Bounds for FCNC and the Pseudoscalar Higgs mass in the General Two Higgs Doublet Model type III using $g-2$ muon factor

Current muon anomalous magnetic moment data have challenged the SM, and seems to open a window to new Physics. Since the difference between SM and experimental predictions is approximately $2.6σ$. 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 Flavor Changing Yukawa couplings (FC) 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.

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