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A. E. Cárcamo Hernández

Publications and source records attributed to A. E. Cárcamo Hernández.

At least 37 records · Page 2Linked to original sources

Phenomenological aspects of the fermion and scalar sectors of a $S_4$ flavored 3-3-1 model

We proposed a viable and predictive model based on the $SU(3)_C \times SU(3)_L \times U(1)_X$ gauge symmetry, supplemented by the global $U(1)_{Lg}$ symmetry, the $S_4$ family symmetry and several auxiliary cyclic symmetries, which successfully reproduces the experimentally observed SM fermion mass and mixing pattern. The tiny active neutrino masses are generated through an inverse seesaw mechanism mediated by right-handed Majorana neutrinos. The model is consistent with the SM fermion masses and mixings and successfully accommodates the current Higgs diphoton decay rate constraints as well as the constraints arising from oblique $S$, $T$ and $U$ parameters and we studied the meson mixing due to flavor changing neutral currents mediated by heavy scalars, finding parameter space consistent with experimental constraints.

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Left-Right model with radiative double seesaw mechanism

We propose an extended Left-Right symmetric model with an additional global symmetry $U(1)_X$, which after spontaneous symmetry breaking collapses to a residual subgroup $\mathbb{Z}_2$, ensuring that the light active neutrino masses are generated via a double seesaw mechanism at two loop level, with the Dirac submatrix arising at one loop. It also guarantees one loop level masses for the SM charged fermions lighter than the top quark and protects Dark Matter (DM) candidates of the model. To the best of our knowledge our model has the first implementation of the radiative double seesaw mechanism with the Dirac submatrix generated at one loop level. We show that the model can successfully accommodate the observed pattern of SM fermion masses as well as mixings and is compatible with the constraints arising from the muon $g-2$ anomaly, neutrinoless double beta decay and DM.

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Gravitational waves from a scotogenic two-loop neutrino mass model

We propose a framework to account for neutrino masses at the two-loop level. This mechanism introduces new scalars and Majorana fermions to the Standard Model. It is assumed the existence of a global $\mathrm{U(1)\times \mathcal{Z}_2}$ symmetry which after partial breaking provides the stability of the dark matter candidates of the theory. The rich structure of the potential allows for the possibility of first-order phase transitions (FOPTs) in the early Universe which can lead to the generation of primordial gravitational waves as one of the potentially observable signatures of this model. Taking into account relevant constraints from lepton flavour violation, neutrino physics as well as the trilinear Higgs couplings at next-to-leading order accuracy, we have found a wide range of possible FOPTs which are strong enough to be probed at the proposed gravitational-wave interferometer experiments such as LISA.

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Phenomenology of 3-3-1 models with radiative inverse seesaw mechanism

We propose two models based on the $SU(3)_C \times SU(3)_L \times U(1)_X$ gauge symmetry, each incorporating distinct inverse seesaw mechanisms for generating neutrino masses at the radiative level. Therefore, neutrino masses are suppressed by the radiative nature of the mass generation mechanism, which occurs after the spontaneous breaking of the global lepton number symmetry. Both scenarios discussed here are characterized by the presence of vector-like charged leptons, which are involved in generating the masses of the Standard Model charged leptons. These additional vector-like fermions contribute to the anomalous magnetic moments of the electron and the muon. We perform a detailed analysis of the scalar sectors, show that these models can successfully accommodate the observed baryon asymmetry through resonant leptogenesis, and compute charged lepton flavor-violating decays, such as $μ\rightarrow e γ$. We discuss the constraints of the model arising from these processes and those associated the non-unitarity of the lepton mixing matrix.

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Predictive linear seesaw model with $Δ\left( 27\right) $ family symmetry

We consider a model that accounts for the smallness of neutrino masses through the linear seesaw mechanism and employs a $Δ(27)$ family symmetry to address the flavour problem. The model is predictive in the leptonic sector and faces constraints from Lepton Flavour Violation processes, namely $μ\to e γ$, which indicate a range for the Right-Handed neutrino mass.

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Dark Matter from a Radiative Inverse Seesaw Majoron Model

We propose a Majoron-like extension of the Standard Model with an extra global $U(1)_X$-symmetry where neutrino masses are generated through an inverse seesaw mechanism at the 1-loop level. In contrast to the tree-level inverse seesaw, our framework contains dark matter (DM) candidates stabilized by a residual $\mathcal{Z}_2$-symmetry surviving spontaneous breaking of the $U(1)_X$-group. We explore the case in which the DM is a Majorana fermion. Furthermore, we provide parameter space regions allowed by current experimental constraints coming from the dark matter relic abundance, (in)direct detection, and charged lepton flavor violation.

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Fermion mass hierarchy in an extended left-right symmetric model

We present a Left-Right symmetric model that provides an explanation for the mass hierarchy of the charged fermions within the framework of the Standard Model. This explanation is achieved through the utilization of both tree-level and radiative seesaw mechanisms. In this model, the tiny masses of the light active neutrinos are generated via a three-loop radiative inverse seesaw mechanism, with Dirac and Majorana submatrices arising at one-loop level. To the best of our knowledge, this is the first example of the inverse seesaw mechanism being implemented with both submatrices generated at one-loop level. The model contains a global $U(1)_{X}$ symmetry which, after its spontaneous breaking, allows for the stabilization of the Dark Matter (DM) candidates. We show that the electroweak precision observables, the electron and muon anomalous magnetic moments as well as the Charged Lepton Flavor Violating decays, $μ\rightarrow e γ$, are consistent with the current experimental limits. In addition, we analyze the implications of the model for the $95$ GeV diphoton excess recently reported by the CMS collaboration and demonstrate that such anomaly could be easily accommodated. Finally, we discuss qualitative aspects of DM in the considered model.

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Global analysis and LHC study of a vector-like extension of the Standard Model with extra scalars

We perform a global analysis of a vector-like extension of the Standard Model, which also features additional doublet and singlet scalars. The usual Yukawa interactions are forbidden in this setup by an extra U(1) global symmetry and the masses of the second and third family quarks and leptons are generated via the mixing with the vector-like sector. We identify three best-fit benchmark scenarios which satisfy the constraints imposed by the stability of the scalar potential, the perturbativity of the coupling constants, the measurement of the muon anomalous magnetic moment and the non-observation of the flavor violating tau decays. We show that dominant contributions to the muon $(g-2)$ originate in this model from the charged Higgs/neutral lepton one-loop diagrams, thus correcting an inaccurate statement than can be found in the literature. We also perform a detailed LHC analysis of the benchmark scenarios. We investigate the experimental constraints stemming from direct searches for vector-like quarks, vector-like leptons and exotic scalars. While we show that the model is not currently tested by any collider experiment, we point out that decays of a heavy Higgs boson into two tau leptons may offer a smoking gun signature for the model verification in upcoming runs at the LHC.

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Linear seesaw mechanism from dark sector

We propose a minimal model where a dark sector seeds neutrino mass generation radiatively within the linear seesaw mechanism. Neutrino masses are calculable, since tree-level contributions are forbidden by symmetry. They arise from spontaneous lepton number violation by a small Higgs triplet vacuum expectation value. Lepton flavour violating processes e.g. $μ\to eγ$ can be sizeable, despite the tiny neutrino masses. We comment also on dark-matter and collider implications.

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Higgs sector phenomenology in the 3-3-1 model with an axionlike particle

The scalar sector of the 3-3-1 model with axion like particle is studied in detail. In the model under consideration, there are two kinds of scalar fields: the bilepton scalars carrying lepton number two and the ordinary ones without lepton number. We show that there is no mixing among these two kinds of scalar fields. We analyze in detail the CP-odd scalar sector of the model to find the physical fields of the axion like particle and a pseudoscalar with mass in the range 100 GeV to 1 TeV. The results are different from others which have been published before. The CP-even scalar sector of the model is analyzed as well. The results of our analysis of the scalar sector allow us to accommodate scalar masses in the $100$ GeV-$1$ TeV region. Furthermore we analyze the implications of the model in several flavor changing neutral decays of the top quark as well as in rare top quark decays. Besides that, the leptonic decays of the SM like Higgs boson as well as the meson oscillations are also analyzed. Our numerical analysis show that the model under consideration is consistent with the experimental constraints imposed by these processes.

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Flavor changing interactions confronted with meson mixing and hadron colliders

We have witnessed some flavor anomalies appeared in the past years, and explanations based on extended gauge sectors are among the most popular solutions. These beyond the Standard Model (SM) theories often assume flavor changing interactions mediated by new vector bosons, but at the same time they could yield deviations from the SM in the $K^{0}-\bar{K}^{0}$, $D^{0}-\bar{D}^{0}$, $B^0_d-\bar{B^0}_d$ and $B^0_s-\bar{B^0}_s$ meson systems. Using up-to-date data on the mass difference of these meson systems, we derive lower mass bounds on vector mediators for two different parametrizations of the quark mixing matrices. Focusing on a well-motivated model, based on the fundamental representation of the weak SU(3) gauge group, we put our findings into perspective with current and future hadron colliders to conclude that meson mass systems can give rise to bounds much more stringent than those from high-energy colliders and that recent new physics interpretations of the $b\rightarrow s$ and $R(D^{\ast})$ anomalies are disfavored.

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Fermion masses and mixings, dark matter, leptogenesis and $g-2$ muon anomaly in an extended 2HDM with inverse seesaw

We propose a predictive $Q_4$ flavored 2HDM model, where the scalar sector is enlarged by the inclusion of several gauge singlet scalars and the fermion sector by the inclusion of right handed Majorana neutrinos. In our model, the $Q_4$ family symmetry is supplemented by several auxiliary cyclic symmetries, whose spontaneous breaking produces the observed pattern of SM charged fermion masses and quark mixing angles. The light active neutrino masses are generated from an inverse seesaw mechanism at one loop level thanks to a remnant preserved $Z_2$ symmetry. Our model succesfully reproduces the measured dark matter relic abundance and is consistent with direct detection constraints for masses of the DM candidate around $\sim$ 6.3 TeV. Furthermore, our model is also consistent with the lepton and baryon asymmetries of the Universe as well as with the muon anomalous magnetic moment

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Heavy singly charged Higgs bosons and inverse seesaw neutrinos as origins of large $(g-2)_{e,μ}$ in two higgs doublet models

We show that simple extensions of two Higgs doublet models consisting of new heavy neutrinos and a singly charged Higgs boson singlet can successfully explain the experimental data on muon and electron anomalous magnetic moments thanks to large chirally-enhanced one-loop level contributions. These contributions arise from the large couplings of inverse seesaw neutrinos with singly charged Higgs bosons and right-handed charged leptons. The regions of parameter space satisfying the experimental data on $(g-2)_{e,μ}$ anomalies allow heavy singly charged Higgs boson masses above the TeV scale, provided that heavy neutrino masses are above few hundred GeV, the non-unitary part of the active neutrino mixing matrix must be large enough, two singly charged Higgs bosons are non degenerate, and the mixing between singly charged Higgs bosons must be non-zero.

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Lepton masses and mixings, and muon anomalous magnetic moment in an extended $B-L$ model with type I seesaw mechanism

We propose a $B-L$ model combined with the $S_4\times Z_3\times Z_4$ discrete symmetry which successfully explains the recent $3+1$ sterile - active neutrino data. The smallness of neutrino mass is obtained through the type-I seesaw mechanism. The active-active and sterile-active neutrino mixing angles are predicted to be consistent with the recent constraints in which $0.3401\, (0.3402) \leq \sin^2θ_{12}\leq 0.3415\, (0.3416), \, 0.456\, (0.433) \leq \sin^2θ_{23}\leq 0.544\, (0.545), \, 2.00\, (2.018) \leq 10^2\times \sin^2θ_{13}\leq 2.405\, (2.424),\,\, 156 \, (140.8) \leq δ^{(\circ)}_{CP}\leq 172\, (167.2)$ for normal (inverted) ordering of the three neutrino scenario, and $0.015 \,(0.022) \leq s^2_{14}\leq 0.045 \,(0.029), \, 0.005 (0.0095)\leq s^2_{24}\leq 0.012\, (0.012), \, 0.003 \,(0.009)\leq s^2_{34} \leq 0.011$ for normal (inverted) ordering of the $3+1$ neutrino scenario. Our model predicts flavour conserving leptonic neutral scalar interactions and successfully explains the muon $g-2$ anomaly.

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An extended 3-3-1 model with radiative linear seesaw mechanism

Motivated by the recent muon anomalous magnetic moment (g-2) measurement at FERMILAB and non-zero neutrino masses, we propose a model based on the $SU(3)_C \times SU(3)_L \times U(1)_X$ (3-3-1) gauge symmetry. The most popular 3-3-1 models in the literature require the presence of a scalar sextet to address neutrino masses. In our work, we show that we can successfully implement an one-loop linear seesaw mechanism with right-handed neutrinos, and vector-like fermions to nicely explain the active neutrino masses, and additionally reproduce the recent Muon g-2 result, in agreement with existing bounds.

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Fermion masses and mixings and $g-2$ muon anomaly in a 3-3-1 model with $D_4$ family symmetry

We propose a predictive model based on the $SU(3)_C\times SU(3)_L\times U(1)_X$ gauge symmetry, which is supplemented by the $D_4$ family symmetry and several auxiliary cyclic symmetries whose spontaneous breaking produces the observed SM fermion mass and mixing pattern. The masses of the light active neutrinos are produced by an inverse seesaw mechanism mediated by three right handed Majorana neutrinos. To the best of our knowledge the model corresponds to the first implementation of the $D_4$ family symmetry in a $SU(3)_C\times SU(3)_L\times U(1)_X$ theory with three right handed Majorana neutrinos and inverse seesaw mechanism. Our proposed model successfully accommodates the experimental values of the SM fermion mass and mixing parameters, the muon anomalous magnetic moment as well as the Higgs diphoton decay rate and meson oscillations constraints. The consistency of our model with the muon anomalous magnetic moment requires charged exotic vector like leptons at the TeV scale.

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Can the muon anomalous magnetic moment and the $B$ anomalies be simultaneously explained in a minimally extended $Z^{\prime}$ model?

We analyze the implications of an extended 2HDM theory in quark masses and mixings, electroweak precision tests, charged lepton flavor violating (CLFV) decays, neutrino trident production, B meson, $g-2$ muon and W anomalies. In the extended 2HDM theory considered in this work, the SM gauge symmetry is enlarged by the local $U(1)^{\prime}$ symmetry, whereas its scalar and fermion sectors are augmented by the inclusion of a gauge singlet scalar and vectorlike fermions, respectively. Within the framework of this model, we determine the allowed ranges of the $Z^{\prime}$ gauge boson mass consistent with the constraints arising from neutrino trident production, $R_{K^{*}}$ anomaly, $B_{s}$ meson oscillation. We conclude the $R_{K^{*}}$ and muon $g-2$ anomalies cannot be simultaneously explained by the same new physics under all the constraints. Besides that, we found that the new physics sources, the $Z^{\prime}$ and non SM scalars cannot be connected via the scalar potential. Furthermore, we have found that the model under consideration can successfully comply with the constraints arising from oblique $T,S,U$ parameters as well as with the $W$ mass and $g-2$ muon anomalies. In particular we found that the muon $g-2$ anomaly, whose dominant contribution arises from the one loop level scalar exchange, can be successfully accommodated within the $2σ$ experimentally allowed range.

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An $A_5$ inverse seesaw model with perturbed golden ratio mixing

We propose a theory based on the $A_5$ discrete group which successfully accounts for lepton masses and mixings. In the proposed model, the neutrino masses arise from an inverse seesaw mechanism. The leptonic mixing consists in a perturbed golden ratio mixing pattern with a strong correlation arising between the leptonic mixing observables, which can be expressed as $θ_{13}$ predicting the other mixing angles and the Dirac CP phase.

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