arXiv subjects

O. Félix-Beltrán

Publications and source records attributed to O. Félix-Beltrán.

16 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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arXiv2025

Lepton flavor violation in photon-induced electron-muon pairs at the HL-LHC

We show the outstanding potential of the High-Luminosity LHC (HL-LHC) to discover charged lepton flavor violation (cLFV) via the ultra-peripheral process $γγ\to e^\pmμ^\mp$. Using a gauge-invariant Effective Field Theory (EFT) framework -consistent with the most stringent bounds from radiative decays- we perform a full Monte Carlo analysis with multivariate techniques. Our results show that a $5σ$ discovery is achievable with an integrated luminosity of $\mathcal{L}_{\rm int} \gtrsim 2700$ fb$^{-1}$ for favorable benchmark scenarios. This study establishes photon-fusion at the HL-LHC as a powerful probe of cLFV, strongly motivating dedicated searches by the experimental collaborations.

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arXiv2025

Single Higgs boson production in association with a top quark through FCNSI

We study the production and possible detection of a single Higgs boson in association with a top quark in proton-proton collisions ($pp \to th + X$) at the High-Luminosity Large Hadron Collider. This process absent in the Standard Model is predicted by other models such as the Two-Higgs Doublet Model of type III, which is the theoretical framework adopted in this work. Promising results are found for specific scenarios of the model parameter space, which consist mainly of the parameters $\tanβ$, $\cos(α-β)$ and the parameter $χ_{tc}$, responsible for the Flavor-Changing Neutral Scalar Interactions (FCNSI). Using the machine learning \textit{Boosted Decision Trees} algorithm and considering a systematic uncertainty of $5\%$, we predict \textit{signal significances} at level of $5σ$ for $\tanβ=1$, $\cos(α-β)=0.1$, $χ_{tc}=5$, and integrated luminosities {$\mathcal{L}_{\rm int}\gtrsim2700~fb^{-1}$}. Likewise, we also predict a \textit{signal significance} $σ\approx 4.4$ for $\tanβ=1$, $\cos(α-β)=0.1$, $χ_{tc}=3$, and integrated luminosities $\mathcal{L}_{\rm int} = 3000~fb^{-1}$, which consider the upper limit given by HL-LHC projection on $\mathcal{BR}(t\to ch)$.

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arXiv2025

Prospects for observing a novel photon-induced $H^-H^+$ production at HL-LHC

We study the production of charged scalar boson pairs via photon-induced $H^{-}H^{+}$ in $pp$ collisions at the forthcoming High Luminosity Large Hadron Collider (HL-LHC). The predictions are based on the Two-Higgs Doublet Model type-III, since it predicts large branching ratios of the channel decay $H^{\pm}\to τ^{\pm}ν_τ$, which is the one we focus on. Motivated by the current excess of events in the process $\mathcal{BR}(t\to H^\pm b)\times \mathcal{BR}(H^\pm\to cb)$ for $M_{H^{\pm}}=130$ GeV, we explore charged Higgs bosons masses $M_{H^{\pm}}$ among 100-150 GeV. According to benchmarks points allowed by experimental constraints, and including a systematic uncertainty of 5$\%$, we obtain for the process of $H^-H^+\to τν_ττν_τ\to eμ+\slashed{E}_T$ a \textit{signal significance} at $5σ$ ($3σ$) for $M_{H^{\pm}}=100$ GeV ($100\leq M_{H^\pm} \leq 136$ GeV) with 3000 $fb^{-1}$ ($\gtrsim 1000\,fb^{-1}$) integrated luminosity, which would be the last stage foreseen for Large Hadron Collider machine.

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arXiv2024

Lessons from LHC on the LFV Higgs decays $h \to \ell_a \ell_b$ in the Two-Higgs Doublet Models

The non-conservation of the lepton number has been explored at the LHC through the Lepton-Flavor Violating (LFV) Higgs decays $h\to\ell_a\ell_b$, with $\ell_{a,\,b}=e,\,μ,\,τ$ $(a \neq b)$. Current limits on these decays are a source of valuable information on the structure of the Yukawa and Higgs sectors. The LFV Higgs couplings can arise within the general Two-Higgs Doublet Model (2HDM); the predicted rates for these decay modes depend on the specific Yukawa structure being considered, ranging from a vanishing branching ratio at tree-level for some versions (2HDM-I, II, X, Y), up to large and detectable ratios within the general 2HDM-III. An attractive scenario is given by the texturized version of the model (2HDM-Tx), with the Yukawa matrices having some texture zeros, such as the minimal version with the so-called Cheng-Sher ansazt. We study the constraints on the parameter space of the 2HDM provided by experimental and theoretical restrictions, and use them to study the detection of LFV Higgs modes at LHC. We find several encouraging scenarios to the search for the decay $h \toτμ$ that could be achieved in the High-Luminosity LHC. On the other hand, LFV Higgs couplings can also be induced at one-loop level in the 2HDM with neutrino masses, with the loops being mediated by neutrino interactions; we find that the resulting branching ratios are of order $10^{-7}$ at best, which is out of the reach of current and future phases of the LHC.

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arXiv2023

Signatures of Dipolar Dark Matter on Indirect Detection

In this work we study the annihilation of fermionic dark matter, considering it as a neutral particle with non-vanishing magnetic ($M$) and electric ($D$) dipole moments. Effective cross section of the process $χ\overlineχ \rightarrow γγ$ is computed starting from a general form of the coupling $χ\overlineχ γ$ in the framework of an extension of the Standard Model. By taking into account the annihilation of dark matter pairs into mono-energetic photons, we found that for masses of $O(10^2)$ GeV, an electric dipole moment $\sim 10^{-16}\, \textrm{e cm}$ is required to satisfy the current relic density inferences. Additionally, in order to pin down models viable to describe the physics of dark matter in the early Universe, we also constrain our model according to recent measurements of the temperature anisotropies of the cosmic microwave background radiation, and report constraints to the electric and magnetic dipole moments for a range of masses within our model.

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arXiv2022

The General One-loop Structure for the LFV Higgs Decays $H_r \to l_a l_b$ in multi-Higgs Models with Neutrino Masses

In this paper we present general formulae for the calculation of LFV Higgs decays $H_r \to l_a l_b$ at one-loop, with $H_r$ being part of the Higgs spectrum of a generic multi-scalar extension of the Standard Model (SM) with neutrino masses. We develop a method based on a classification of the particles appearing in the loop diagrams (scalars, fermions and vectors), and by identifying the corresponding couplings, we are able to present compact expressions for the form factors involved in the amplitudes. Our results are applicable to models where Flavor Changing Neutral Currents (FCNC) are forbidden at tree-level, but change of flavor is induced by charged currents. Then, as applications of our formalism, we evaluate the branching ratio for the mode $h \to l_a l_b$, for two specific models: the See-Saw Type I-$ν$SM and the Scotogenic model (here $h = H_1$ corresponds to the SM-like Higgs boson); we find that the largest branching ratio for SM-like Higgs $h$ boson within the $ν$SM is of the order $\mathcal{BR}(h\to μτ)\simeq 10^{-12}$, while for the Scotogenic model we find $\mathcal{BR}(h\to l_a l_b)\lesssim 10^{-9}$, which satisfy the latest experimental LHC results.

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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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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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arXiv2015

Analysis of the quark sector in the 2HDM-III with a four-zero Yukawa texture using the most recent data on the CKM matrix

In this letter we analyse, in the context of the general 2-Higgs Doublet Model, the structure of the Yukawa matrices, $\widetilde{ \bf Y}_{ _{1,2} }^{q}$, by assuming a four-zero texture ansatz for their definition. In this framework, we obtain compact expressions for $\widetilde{ \bf Y}_{ _{1,2} }^{q}$, which are reduced to the Cheng and Sher ansatz with the difference that they are obtained naturally as a direct consequence of the invariants of the fermion mass matrices. Furthermore, in order to avoid large flavour violating effects coming from charged Higgs exchange, we consider the main flavour constraints on the off-diagonal terms of Yukawa texture {{$\left( \widetildeχ_{j}^q \right)_{kl}$}} ($k\neq l$). We perform a $χ^2$-fit based on current experimental data on the quark masses and the Cabibbo-Kobayashi-Maskawa mixing matrix ${ \bf V}_{\rm CKM }$. Hence, we obtain the allowed ranges for the parameters $\widetilde{ \bf Y}_{ _{1,2} }^{q}$ at 1$σ$ for several values of $\tan β$. The results are in complete agreement with the bounds obtained taking into account constraints on Flavour Changing Neutral Currents reported in the literature.

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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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arXiv2010

Electroweak right-handed neutrinos and new signals at the LHC

We explore in detail the Higgs phenomenology that results in a model where right-handed neutrinos have a mass scale of the order of the electroweak scale. In this model all scales arise from spontaneous symmetry breaking, and this is achieved with a Higgs sector that includes an extra Higgs singlet in addition to the standard model Higgs doublet. The scalar spectrum includes two neutral CP-even states ($h$ and $H$ with $m_{h} < m_{H}$)and a neutral CP-odd state ($σ$) that can be identified as a pseudo-Majoron. The parameter of the Higgs potential are constrained using a perturbativity criteria. Higgs BR and cross-sections are discussed, with special emphasis on the detection at the LHC.

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arXiv2010

Implications of Yukawa Textures in the decay $H^+ \to W^+ γ$ within the 2HDM-III

We discuss the implications of assuming a four-zero Yukawa texture for the charged Higgs decay $H^+ \to W^+ γ$ at one-loop level, within the context of the general 2-Higgs Doublet Model of Type III. We begin by presenting a detailed analysis of the charged Higgs boson couplings with heavy quarks and the resulting effects on its decays. In particular, we present the possible enhancement of the decay $H^+ \to W^+ γ$, whose branching ratio could be of the order $\sim 10^{-1}$, for charged Higgs mass of the order 180 GeV. These parameters can still avoid the $B \to X_s γ$ constraint and the perturbativity bound. The production of charged Higgs bosons is also sensitive to the modifications of its couplings, and we evaluate the events rates at the LHC, including the `direct' $c\bar{b}\to H^++c. c.$ and `indirect' $q\bar q, gg \to \bar t b H^++c. c.$ production channels. We get an event rate of order 60 (120) for `direct' (`indirect') production reaction, and including decay $H^+ \to W^+ γ$ in the final state, with an integrated luminosity of $10^5$ $pb^{-1}$.

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