arXiv subjects

E. Barradas-Guevara

Publications and source records attributed to E. Barradas-Guevara.

11 recordsLinked to original sources

arXiv2026

Spontaneous CP breaking in $S_3$ flavored Higgs sector with soft-breaking terms

We analyze the Higgs sector of the minimal $S_3$-invariant extension of the Standard Model including spontaneous and explicit CP violation arising from the spontaneous electroweak symmetry breaking. This extended Higgs sector includes three SU(2) Higgs doublets with and without complex vev's, which ones providing an interesting scenario to analyze the Higgs masses spectrum, trilinear Higgs self-couplings and CP violation. We present how the spontaneous electroweak symmetry breaking coming from three SU(2) Higgs doublets gives an interesting scenario when spontaneous CP violation arises from the Higgs doublet $Φ_S$, singlet under $S_3$. Furthermore, a numerical analysis of the Higgs masses and trilinear Higgs self-couplings is presented. Particularly, we find a physical solution for the scenario in which spontaneous CP break is provided by $Φ_S$. The analysis of soft breaking to $S_3$ symmetry including CP breaking terms opens up a rich parameter space, with Higgs masses and trilinear Higgs self-couplings favoring one of the Higgs bosons as a SM-like type Higgs boson.

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arXiv2026

Systematic analysis of fermionic masses and flavor mixings: a model-independent approach

In a model-independent context, we perform a systematic and detailed study of the fermion flavor masses and mixings. In this analysis, we present a most general parameterization form of the $3 \times 3$ mass matrix, as well as the Pontecorvo-Maki-Nakagawa-Sakata flavor mixing matrix, in terms of the fermionic masses and some free parameters. A likelihood test using the $χ^2$ statistic is implemented to evaluate whether the theoretical expressions for the leptonic flavor mixing angles also reproduce the experimental data. The results of the $χ^2$ fit show that the theoretical expressions obtained for the Pontecorvo-Maki-Nakagawa-Sakata mixing matrix correctly reproduce the actual experimental data on neutrino oscillations.

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arXiv2022

Deviation to the Tri-Bi-Maximal flavor pattern and equivalent classes

In the model-independent context, where the neutrino mass matrix is assumed to be diagonalized by means of a unitary matrix that possess the Tri-Bi-Maximal (TBM) flavor mixing pattern. We present an analysis where the TBM deviation is explored by considering different forms, with texture zeros, for the charged lepton mass matrix. These last mass matrices are classified into equivalent classes. We are interested in the charged lepton mass matrices with the minimum free parameter number, $i.e.$ the maximum number of texture zeros, that allows us to correctly reproduce the reactor mixing angle value. We show a deviation from the TBM pattern in terms of the charged lepton masses as well as the theoretical expressions and their parameter space for the mixing angles. Finally, we present the phenomenological implications of numerical values of the "Majorana-like" phase factors on the neutrinoless double-beta decay.

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arXiv2017

On the lepton CP violation in a $ν$2HDM with flavor

In this work we propose an extension to the Standard Model in which we consider the model 2HDM type-III plus massive neutrinos and the horizontal flavor symmetry $S_{3}$ $(ν$2HDM$\otimes S_3)$. In the above framework and with the explicit breaking of flavor symmetry $S_{3}$, the Yukawa matrices in the flavor adapted basis are represented by means of a matrix with two texture zeroes. Also, the active neutrinos are considered as Majorana particles and their masses are generated through type-I seesaw mechanism. The unitary matrices that diagonalize the mass matrices, as well as the flavor mixing matrices, are expressed in terms of fermion mass ratios. Consequently, in the mass basis the entries of the Yukawa matrices naturally acquire the form of the so-called {\it Cheng-Sher ansatz}. For the leptonic sector of $ν$2HDM$\otimes S_3$, we compare, through a $χ^{2}$ likelihood test, the theoretical expressions of the flavor mixing angles with the masses and flavor mixing leptons current experimental data. The results obtained in this $χ^{2}$ analysis are in very good agreement with the current experimental data. We also obtained an allowed value ranges for the "Dirac-like" phase factor, as well as for the two Majorana phase factors. Furthermore, we study the phenomenological implications of these numerical values of the CP-violation phases on the neutrinoless double beta decay, and for Long Base-Line neutrino oscillation experiments such as T2K, NO$ν$A, and DUNE.

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arXiv2017

Linking LFV Higgs decays $h\to \ell_i \ell_j$ with CP violation in multi-scalar models

The study of LFV decays of the Higgs boson, $h\to \ell_i \ell_j$, has become an active research subject both from the experimental and theoretical points of view. Such decays vanish within the SM and are highly suppressed in several theoretical extensions. Due to its relevance and relative simplicity to reconstruct the signal at future colliders, it is an important tool to probe SM extensions where it could reach detectable levels. Here we identify a mechanism that induces LFV Higgs interactions, by linking it with the appearance of CP violation in the scalar sector, within the context of general multi-Higgs models. We then focus on the simplest model of this type to study its phenomenology. The scalar sector of this minimal model consisting of a Higgs doublet and a Froggatt--Nielsen (FN) (complex) singlet is studied thoroughly, including the scalar spectrum and the Yukawa interactions. Constraints on the parameters of the model are derived from low-energy observables and LHC Higgs data, which is then applied to study the resulting predicted rates for the decay $h\rightarrow τμ$. Overall, branching ratios for $h \rightarrow τμ$ of the order $10^{-3}$ are obtained within this approach consistent with all known constraints.

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arXiv2016

CP breaking in $S(3)$ flavoured Higgs model

We analyze the Higgs sector of the minimal $S(3)$-invariant extension of the Standard Model including CP violation arising from the spontaneous electroweak symmetry breaking. This extended Higgs sector includes three SU(2) doublets Higgs fields with complex vev's providing an interesting scenario to analyze the Higgs masses spectrum, trilinear Higgs self-couplings and CP violation. We present how the spontaneous electroweak symmetry breaking coming from three $S(3)$ Higgs fields gives an interesting scenario with nine physical Higgs and three Goldstone bosons when spontaneous CP violation arises from the Higgs field $S(3)$ singlet $H_S$. Furthermore, a numerical analysis of the Higgs masses and trilinear Higgs self-couplings is presented. Particularly, we find a physical solution for the scenario in which spontaneous CPB is provided by $H_S$. In this scheme, the scalar Higgs $H^0_1$ is identified, whose mass is 125 GeV and $λ_{H_{1}^0 H_{1}^0 H_{1}^0} \sim λ_{h^0 h^0 h^0}^{SM}$.

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arXiv2016

Higgs sector with spontaneous CP violation in $S(3)$ Standard Model

Conditions for spontaneous Charge-Parity (CP) violation in the scalar potential sector of general $S(3)$ Higgs-doublet model (3HDM) are analyzed. An analysis of the Higgs sector of the minimal $S(3)$-invariant extension of the Standard Model including CP violation arising from the spontaneous breaking of the electroweak symmetry is presented. This extended Higgs sector with three SU(2) doublets Higgs fields with complex vev's provides an interesting scenario to analyze the Higgs masses spectrum, trilinear self-couplings and CP violation. We present how the spontaneous electroweak symmetry breaking, coming from three $S(3)$ Higgs fields, gives an interesting scenario with nine physical Higgs and three Goldstone bosons, when spontaneous CP violation arises from the Higgs field $S(3)$ singlet $H_S$.

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arXiv2016

Analysis of the Lepton Mixing Matrix in the Two Higgs Doublet Model

In the theoretical framework of Two Higgs Doublet Model (2HDM) plus three right-handed neutrinos we consider a universal treatment for the mass matrices, aside from that the active neutrinos acquire their small mass through the type-I seesaw mechanism. Then, as long as a matrix with four-zero texture is used to represent the right-handed neutrinos and Yukawa matrices, we obtain a unified treatment where all fermion mass matrices have four-zero texture. We obtain analytical and explicit expressions for the lepton flavour mixing matrix PMNS in terms of fermion masses and parameters associated with the 2HDM-III. Further, we compare these expressions of the PMNS matrix with the most up to date values of masses and mixing in the lepton sector, via a likelihood test $χ^{2}$. We find that the analytical expressions that we derived reproduce remarkably well the most recent experimental data of neutrino oscillations.

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arXiv2014

S(3) flavoured Higgs model trilinear self-couplings

In this work, we analyze the Higgs sector of the minimal $S(3)$-invariant extension of the Standard Model is performed. Considering three Higgs fields, which are SU(2) doublets, and CP invariant, we compute the exact and analytical physical Higgs boson masses in terms of the Higgs potential parameters and the scalar Higgs matrix rotation angle $θ_S$ and $w_3$ ($\tanθ_P=\tanθ_C=\tan^{-1}ω_3$), related to the pseudoscalar and charged Higgs matrix rotation angles $θ_P$ and $θ_C$ respectively. Furthermore, within this model we can also write down in an explicit form the trilinear self-couplings $λ_{ijk}$ in terms of the Higgs masses and two free parameters, $θ_S$ and $w_3$. Moreover, we show that the Higgs masses and trilinear Higgs bosons self-couplings are closely linked to the Higgs potential structure given by the discrete symmetry $S(3)$, which can be helpful to distinguish this model from other extensions. In our analysis the lightest Higgs boson mass is taken to be fixed to 125 GeV. In concordance with the results reported in the literature for other Standard Model extensions, it find that the numerical values $λ_{ijk}$ of the minimal $S(3)$-invariant extension of the Standard Model are significantly different from the trilinear Higgs self-coupling of the Standard Model.

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arXiv2005

The decays h+- -> W-+ h0(a0) within an extension of the MSSM with one complex Higgs triplet

The vertex H+-W-+h0, involving the gauge bosons W-+, the charged (H+-) and the lightest neutral (h0) Higgs bosons, arises within the context of many extensions of the SM, and it can be used to probe the Higgs sector of such extensions via the decay H+- -> W+- h0. We discuss the strength of this vertex for an extension of the MSSM with an additional complex Higgs triplet. By using this model, we find regions of the parameter space where the decay H+- -> W+- h0 is not only kinematically allowed, but it also becomes an important decay mode and in some cases the dominant one.

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arXiv2003

Probing the charged Higgs quantum numbers through the decay H^+ -> W^+ h^0

The vertex H^+_αW^-h^0_β, involving the gauge boson W^+- and the charged (H^+-_α) and neutral Higgs bosons (h^0_β), arises within the context of many extensions of the SM, and it can be used to probe the quantum numbers of the Higgs multiplet. After presenting a general discusion for the expected form of this vertex with arbitrary Higgs representations, we discuss its strength for several specific models, which include: i) the Two-Higgs Doublet Model (THDM), both the generic and the SUSY case, and ii) models with additional Higgs triplets, including both SUSY and non-SUSY cases. We find that in these models, there are regions of parameters where the decay H^+_α-> W^+ h^0_β, is kinematically allowed, and reaches Branching Ratios (BR) that may be detectable, thus allowing to test the properties of the Higgs sector.

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