arXiv subjects

Raymundo Ramos

Publications and source records attributed to Raymundo Ramos.

At least 19 recordsLinked to original sources

arXiv2026

Rolling Down the Leptonic BSM Landscape Using Machine Learning Techniques

In this work, we adapt and apply techniques from machine learning to the exploration of physics beyond the Standard Model in the leptonic sector. Namely, we employ initialization and optimization, as they are applied in machine learning, to minimize a loss function that describes textures or conditions which we want in the neutrino mass matrix. The model free parameters are explored during the optimization, and after training for a number of optimization steps, we obtain matrices that approximately follow the desired forms, as well as their corresponding optimized parameters. We also discuss extensions and additional applications of the ideas presented here in conjunction with other methods based on artificial intelligence.

hep-ph↗

arXiv2025

Exploring the energy landscape of the logarithmic potential: local minima and stationary states

We have performed a detailed exploration of the energy landscape for configurations of points on the sphere, interacting via the logarithmic potential, and corresponding to local minima of the total energy, up to $N = 160$. The growth of $N_{\rm conf}$ (number of distinct configurations) is exponential, as for the Thomson problem, although weaker. Using the techniques described in our previous paper~\cite{Amore25} we have also explored the solution landscape of this problem for $N \leq 24$, and found that the number of stationary states is growing exponentially.

cond-mat.soft↗

arXiv2025

Explaining Data Anomalies over the NMSSM Parameter Space with Deep Learning Techniques

Motivated by recent results from particle physics analyses, we investigate the Next-to-Minimal Supersymmetric Standard Model (NMSSM) as a framework capable of accommodating a range of current data anomalies across low- and high-energy experiments. These include the so-called 95GeV and 650GeV excesses from Higgs studies, the Electro-Weakino excess from Supersymmetry searches, the latest $(g-2)_μ$ measurements as well as potential deviations from Standard Model (SM) predictions that would appear as a consequence in mono-$H$ (where $H=h_{\rm SM}$) and -$Z$ signatures of Dark Matter. Our analysis demonstrates that viable NMSSM parameter regions exist where all these features can be accommodated at the $2σ$ level while remaining consistent with the most up-to-date theoretical and experimental constraints. To identify such regions, we employ an efficient numerical scanning strategy assisted by deep learning techniques. We further present several benchmark points that realize these scenarios, offering promising directions for future phenomenological studies.

hep-ph↗

arXiv2025

A two scalar triplets model as common origin for dark matter, neutrino masses, baryon asymmetry and inflation

We propose an extension of the standard model (SM) by two SU(2) triplet scalars and an inert SU(2) doublet. We demonstrate that this setup can simultaneously produce an inflaton and baryon asymmetry in the early universe, provide a dark matter candidate and explain the smallness of neutrino masses. The two triplets are particularly important as they become mediators for the production of dark matter and the generation of lepton asymmetry, as well as contribute an inflaton. The inert doublet results in a dark matter candidate. The required CP-violation for lepton asymmetry is obtained by interference between the triplet mediators that communicate the dark sector to the SM sector. More precisely, the complex Breit-Wigner propagators of the triplets and their mixing, result in an asymmetric production of leptons and antileptons that is boosted before dark matter freeze-out. In this case, simultaneously achieving enough dark matter relic abundance and proper matter-antimatter asymmetry limits the available parameter space of the model. Moreover, the scalar triplets are coupled non-minimally to gravity and give rise to the inflaton. We calculate the inflationary parameters and check that we can obtain predictions consistent with Planck constraints from 2018. We also perform an analysis of the reheating for the inflaton decays/annihilations to relativistic SM particles.

hep-ph↗

arXiv2024

DLScanner: A parameter space scanner package assisted by deep learning methods

In this paper, we introduce a scanner package enhanced by deep learning (DL) techniques. The proposed package addresses two significant challenges associated with previously developed DL-based methods: slow convergence in high-dimensional scans and the limited generalization of the DL network when mapping random points to the target space. To tackle the first issue, we utilize a similarity learning network that maps sampled points into a representation space. In this space, in-target points are grouped together while out-target points are effectively pushed apart. This approach enhances the scan convergence by refining the representation of sampled points. The second challenge is mitigated by integrating a dynamic sampling strategy. Specifically, we employ a VEGAS mapping to adaptively suggest new points for the DL network while also improving the mapping when more points are collected. Our proposed framework demonstrates substantial gains in both performance and efficiency compared to other scanning methods.

hep-ph↗

arXiv2024

LeStrat-Net: Lebesgue style stratification for Monte Carlo simulations powered by machine learning

We develop a machine learning algorithm to turn around stratification in Monte Carlo sampling. We use a different way to divide the domain space of the integrand, based on the height of the function being sampled, similar to what is done in Lebesgue integration. This means that isocontours of the function define regions that can have any shape depending on the behavior of the function. We take advantage of the capacity of neural networks to learn complicated functions in order to predict these complicated divisions and preclassify large samples of the domain space. From this preclassification we can select the required number of points to perform a number of tasks such as variance reduction, integration and even event selection. The network ultimately defines the regions with what it learned and is also used to calculate the multi-dimensional volume of each region.

hep-ph↗

arXiv2024

Exploration of Parameter Spaces Assisted by Machine Learning

We demonstrate two sampling procedures assisted by machine learning models via regression and classification. The main objective is the use of a neural network to suggest points likely inside regions of interest, reducing the number of evaluations of time consuming calculations. We compare results from this approach with results from other sampling methods, namely Markov chain Monte Carlo and MultiNest, obtaining results that range from comparably similar to arguably better. In particular, we augment our classifier method with a boosting technique that rapidly increases the efficiency within a few iterations. We show results from our methods applied to a toy model and the type II 2HDM, using 3 and 7 free parameters, respectively. The code used for this paper and instructions are publicly available on the web.

hep-ph↗

arXiv2024

Relic density and temperature evolution of a light dark sector

We have developed a set of four fully coupled Boltzmann equations to precisely determine the relic density and temperature of dark matter by including three distinct sectors: dark matter, light scalar, and standard model sectors. The intricacies of heat transfer between dark matter (DM) and the standard model sector through a light scalar particle are explored, inspired by stringent experimental constraints on the scalar-Higgs mixing angle and the DM-scalar coupling. Three distinct sectors emerge prior to DM freeze-out, requiring fully coupled Boltzmann equations to accurately compute relic density. Investigation of forbidden, resonance, and secluded DM scenarios demonstrates significant deviations between established methods and the novel approach with fully coupled Boltzmann equations. Despite increased computational demands, this emphasizes the need for improved precision in relic density calculations, underlining the importance of incorporating these equations in comprehensive analyses.

hep-ph↗

arXiv2023

Common origin of dark matter, baryon asymmetry and neutrino masses in the standard model with extended scalars

We propose a model that simultaneously addresses the existence of a dark matter candidate, baryon asymmetry and tiny neutrino masses and mixing by introducing two SU(2) triplet scalars and an inert SU(2) doublet scalar on top of the standard model. The two triplet scalars serve as mediators in generation of lepton asymmetry and determination of relic density of dark matter. They also play an essential role in generation of tiny neutrino masses and inducing CP violation. The inert scalar is regarded as a dark matter candidate. The interference due to complex Breit-Wigner propagators for the triplets will result in CP-asymmetry that depends on the difference between their masses and a relative complex phase between their couplings to standard model leptons. Moreover, the production of lepton asymmetry will be closely tied to the evolution of dark matter, limiting the parameter space where the correct relic abundance and matter-antimatter asymmetry can be simultaneously accomplished.

hep-ph↗

arXiv2022

Implications of the new CDF-II $W$-boson mass on two-Higgs-doublet models

We present the implications of the recent measurement of $W$ boson at CDF II on the two-Higgs-doublet model (2HDM). In the analysis, we impose theoretical bounds such as vacuum stability and perturbative unitarity, and several experimental constraints. In addition, we take into account the measurement of $\sin^2θ_W(m_Z)_{\rm \bar{MS}}$ on top of the CDF $W$-boson mass to investigate how the $S$ and $T$ parameters are determined. We explore two possible scenarios depending on whether the Higgs boson observed at the LHC is the lighter or heavier of $CP$-even neutral Higgs bosons for 2HDM type I and II. Using the results, we show how the parameter space is constrained, and compare it with the one based on the PDG average of $m_W$. Furthermore, we explore phenomenological consequences of electroweak precision observables that can be affected by $m_W$ within the predictions of the 2HDM, and the reduction in parameter space expected from future measurements at the Future Circular Lepton Collider.

hep-ph↗

arXiv2022

Predictions for the Leptonic Dirac CP-Violating Phase

We explore the theoretical constraints on the observable parameters of neutrino mixing on predictions for the leptonic Dirac CP-violating phase within a well-studied class of simple theoretical models that includes a single source of CP violation due to charged lepton corrections. The approach guarantees that a physically meaningful prediction for the most likely values for the leptonic Dirac CP-violating phase is obtained.

hep-ph↗

arXiv2022

Confronting the prediction of leptonic Dirac CP-violating phase with experiments

We update and improve past efforts to predict the leptonic Dirac CP-violating phase with models that predict perturbatively modified tribimaximal or bimaximal mixing. Simple perturbations are applied to both mixing patterns in the form of rotations between two sectors. By translating these perturbed mixing matrices to the standard parameterization for the neutrino mixing matrix we derive relations between the Dirac CP-phase and the oscillation angles. We use these relations together with current experimental results to constrain the allowed range for the CP-phase and determine its probability density. Furthermore, we elaborate on the prospects for future experiments probing on the perturbations considered in this work. We present a model with $A_4$ modular symmetry that is consistent with one of the described perturbed scenarios and successfully predicts current oscillation parameter data.

hep-ph↗

arXiv2021

Shedding light on dark matter with recent muon $(g-2)$ and Higgs exotic decay measurements

Recently, we have witnessed two hints of physics beyond the standard model: A 3.3$σ$ local excess ($M_{A_0} = 52$ GeV) in the search for $H_0\to A_0 A_0\to b\bar{b}μ^{+}μ^{-}$ and a 4.2$σ$ deviation from the SM prediction in the $(g-2)_μ$ measurement. The first excess was found by the ATLAS Collaboration using 139 fb$^{-1}$ data at $\sqrt{s}=13$ TeV. The second deviation is a combination of the results from the Brookhaven E821 and the recently reported Fermilab E989 experiment. We attempt to explain these deviations in terms of a renormalizable simplified dark matter model. Inspired by the null signal result from dark matter (DM) direct detection, we interpret the possible new particle, $A_0$, as a pseudoscalar mediator connecting DM and the standard model. On the other hand, a new vector-like muon lepton can explain these two excesses at the same time while contributiong to the DM phenomenology.

hep-ph↗

arXiv2021

A Sub-GeV Low Mass Hidden Dark Sector of $SU(2)_H \times U(1)_X$

We present a detailed study of the non-abelian vector dark matter candidate $W^\prime$ with a MeV-GeV low mass range, accompanied by a dark photon $A^\prime$ and a dark $Z^\prime$ of similar masses, in the context of a gauged two-Higgs-doublet model with the hidden gauge group that has the same structure as the Standard Model electroweak gauge group. The stability of dark matter is protected by an accidental discrete $Z_2$ symmetry ($h$-parity) which was usually imposed ad hoc by hand. We examine the model by taking into account various experimental constraints including dark photon searches at NA48, NA64, E141, $ν$-CAL, BaBar and LHCb experiments, electroweak precision data from LEP, relic density from Planck satellite, direct (indirect) detection of dark matter from CRESST-III, DarkSide-50, XENON1T (Fermi-LAT), and collider physics from the LHC. The theoretical requirements of bounded from below of the scalar potential and tree level perturbative unitarity of the scalar sector are also imposed. The viable parameter space of the model consistent with all the constraints is exhibited. While a dark $Z^\prime$ can be the dominant contribution in the relic density due to resonant annihilation of dark matter, a dark photon is crucial to dark matter direct detection. We also demonstrate that the parameter space can be further probed by various sub-GeV direct dark matter experimental searches at CDEX, NEWS-G and SuperCDMS in the near future.

hep-ph↗

arXiv2021

Complementary Searches of Low Mass Non-Abelian Vector Dark Matter, Dark Photon and Dark $Z^\prime$

We present a novel study of the non-abelian vector dark matter candidate $W^\prime$ with a MeV$-$GeV low mass range, accompanied by a dark photon $A^\prime$ and a dark $Z^\prime$ of similar masses in the context of a simplified gauged two-Higgs-doublet model. The model is scrutinized by taking into account various experimental constraints including dark photon searches, electroweak precision data, relic density of dark matter together with its direct and indirect searches, mono-jet and Higgs collider physics from LHC. The viable parameter space of the model consistent with all experimental and theoretical constraints is exhibited. While a dark $Z^\prime$ can be the dominant contribution in the relic density due to resonant annihilation of dark matter, a dark photon is crucial to dark matter direct detection. We demonstrate that the parameter space can be further probed in the near future by sub-GeV dark matter experiments like CDEX, NEWS-G and SuperCDMS.

hep-ph↗

arXiv2019

Complex Scalar Dark Matter in G2HDM

The complex scalar dark matter (DM) candidate in the gauged two Higgs doublet model (G2HDM), stabilized by a peculiar hidden parity ($h$-parity), is studied in detail. We explore the parameter space for the DM candidate by taking into account the most recent DM constraints from various experiments, in particular, the PLANCK relic density measurement and the current DM direct detection limit from XENON1T. We separate our analysis in three possible compositions for the mixing of the complex scalar. We first constrain our parameter space with the vacuum stability and perturbative unitarity conditions for the scalar potential, LHC Higgs measurements, plus Drell-Yan and electroweak precision test constraints on the gauge sector. We find that DM dominated by composition of the inert doublet scalar is completely excluded by further combining the previous constraints with both the latest results from PLANCK and XENON1T. We also demonstrate that the remaining parameter space with two other DM compositions can be further tested by indirect detection like the future CTA gamma-ray telescope.

hep-ph↗

arXiv2019

Consistency of Gauged Two Higgs Doublet Model: Gauge Sector

We study the constraints on the new parameters in the gauge sector of gauged two Higgs doublet model using the electroweak precision test data collected from the Large Electron Positron Collider (LEP) at and off the Z-pole as well as the current Drell-Yan and high-mass dilepton resonance data from the Large Hadron Collider (LHC). Impacts on the new parameters by the projected sensitivities of various electroweak observables at the Circular Electron Positron Collider (CEPC) proposed to be built in China are also discussed. We also clarify why the Stüeckelberg mass $M_Y$ for the hypercharge $U(1)_Y$ is set to be zero in the model by showing that it would otherwise lead to the violation of the standard charge assignments for the elementary quarks and leptons.

hep-ph↗

arXiv2018

Consistency of a gauged two-Higgs-doublet model: Scalar sector

We study the theoretical and phenomenological constraints imposed on the scalar sector of the gauged two Higgs doublet model proposed recently as a variant of the popular inert Higgs doublet model of dark matter. The requirements of tree-level vacuum stability and perturbative unitarity in the scalar sector are analyzed in detail. Furthermore, taking into account the constraints from the 125 GeV Higgs boson measurements at the Large Hadron Collider, we map out the allowed ranges for the fundamental parameters of the scalar potential in the model.

hep-ph↗