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T. A. Valencia-Pérez

Publications and source records attributed to T. A. Valencia-Pérez.

11 recordsLinked to original sources
arXiv2026

Beyond the Standard Model Higgs physics: Hunting $h \rightarrow bs$ with Higgs-strahlung at CEPC and FCC-ee

The next generation of circular electron-positron colliders, such as the Circular Electron Positron Collider and the Future Circular Collider, will provide an unprecedented level of precision in probing the properties of the Higgs boson. In this study, we examine the flavor-changing neutral Higgs decay $h\to bs$ produced via the Higgs-strahlung process within the framework of the Two-Higgs-Doublet Model Type III. We identify regions of the parameter space that remain viable after applying stringent constraints from current experimental data. By employing a multivariate analysis based on Boosted Decision Trees, we project that a signal significance of $5σ$ can be achieved, even after accounting for irreducible backgrounds and systematic uncertainties. Our findings show that these future colliders could offer a unique avenue for discovering signatures of physics beyond the standard model.

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arXiv2026

Production of dark matter in association with a Higgs boson via exclusive photon fusion in $pp$ collisions at $\sqrt{s}=13$ TeV

In this work we study the production of a dark matter (DM) particle in association with a Higgs boson via a central exclusive photon-fusion initiated process. We explore this type of production through the Inert Doublet Model plus a complex Singlet (IDMS), where an extension of the Standard Model by an additional $U(1)_X$ gauge symmetry and a $SU(2)$ inert scalar doublet gives rise to a DM candidate $χ$. This particular process involves the collision of two protons exchanging two colorless particles (in our case, photons), from which a central process occurs. Such interaction can be detected in the LHC using forward proton detectors, where the resulting missing mass spectrum can be observed after proton reconstruction, thus allowing a search for physics Beyond the Standard Model (BSM). We present results for different values of the difference of masses of a heavy scalar coming from the complex singlet, the DM candidate and the Higgs boson, $Δ= M_S - M_χ- M_h$, which is the phase space available for the final state in the central exclusive process.

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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

Searching for the Flavon in the diphoton channel at future super hadron colliders

We study the production of a CP-even flavon $H_F$ in proton-proton collisions and the prospects for its detection via the diphoton channel at future super hadron colliders, i.e., $pp\to H_F\toγγ$. The theoretical framework adopted is a model that invokes the Froggatt-Nielsen mechanism with an Abelian flavor symmetry, which includes a Higgs doublet and a complex singlet. We confront the free parameters of the model against theoretical and experimental constraints to find the allowed parameter space, which is then used to evaluate the production cross section of the flavon and the branching ratio of its decay into two photons. We find promising results based on specific benchmark points, achieving signal significances at the level of 5$σ$ for flavon masses in the interval $200\lesssim M_{H_F}\lesssim 450$ and integrated luminosities in the range $5-12$ ab$^{-1}$ at the future High-Energy LHC. On the other hand, the Future hadron-hadron Circular Collider could probe masses up to 1 TeV if it reaches an integrated luminosity of at least 2 ab$^{-1}$.

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arXiv2025

Flavoring the production of Higgs pairs

We present a study on the possibility of observing a hypothetical particle known as the Flavon $H_F$, which is predicted in an extension of the standard model that includes the so-called Froggatt-Nielsen mechanism. The proposed decay channel is through a $b\bar{b}h$ final state, where the Higgs boson $(h)$ decays to a pair of photons or a pair of $b$ quarks $(h\to γγ,\,b\bar{b})$. We found that, under special scenarios of the model parameter space, the processes analyzed could provide evidence for the existence of the Flavon in the next stage of the LHC: the High Luminosity LHC. Specifically, we predict a \textit{signal significance} of $5σ$ ($2σ$) in the $h\to b\bar{b}$ ($h\toγγ$) channel for a Flavon mass of $800$ ($900$) GeV and an integrated luminosity of $2500$ ($3000$) fb$^{-1}$.

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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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arXiv2023

$\texttt{SpaceMath v.2.0}$ with Machine Learning. A $\texttt{Mathematica}$ package for Beyond the Standard Model parameter space searches

\texttt{SpaceMath v.2.0} with Machine Learning is an extension of the previous version which we implement observables related with LHC Higgs boson data and their projections for the High Luminosity and High Energy Large Hadron Collider. In this version we implemented processes with Flavor-Changing Neutral Currents at tree and one-loop level, namely, i) Radiative decays $\ell_i\to\ell_j γ$, ii) $\ell_i\to \ell_j \ell_k \bar{\ell}_k$ decays ($\ell_i=τ,\,μ$, $\ell_{j,\,k}=μ,\,e$, with $\ell_i \neq\ell_j \neq\ell_k$) and iii) anomalous magnetic dipole moment of the muon $δa_μ$. \texttt{SpaceMath v.2.0} is able to find allowed regions for free parameters of models with both real and complex singlets and real and complex doublets using the processes previously mentioned within a friendly interface and an intuitive environment in which the user enters the couplings symbolically, sets parameters and execute \texttt{Mathematica} in the traditional way. As result, both tables as plots with values and areas agree with experimental data are generated. We present examples using \texttt{SpaceMath v.2.0} to analyze the free \textit{Two-Higgs Doublet Model of type III} parameter space, step by step, in order to start new users in a fast and efficient way. Finally, we have implemented in this version of \texttt{SpaceMath} algorithms of Machine Learning to generate specific Benchmark Points to be used directly in numerical evaluations of calculations of physical observables.

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arXiv2022

Single top production via FCNC couplings at an $e^{-}e^{+}$ collider with center-of-mass energy $\sqrt{s}=240$ GeV

Aspects of top quark physics can be studied at a future Circular Electron-Positron Collider (CEPC). In particular, Flavor-Changing Neutral Current interactions (FCNC) of the top quark can be studied even with a center-of-mass energy from $\sqrt{s}\gtrsim m_t$ to $\sqrt{s}=240$ GeV, through the production a single top quark in association with a charm quark, which can arise in several scenarios of new physics. We explore here this signal within the Left-Right Mirror Model, which is a Left-Right model that includes mirror fermions; this model is motivated as a possible solution to the strong CP problem and by its rich phenomenology. We find that for particular scenarios of the model parameters, which are in agreement with the most up-to-date experimental constraints, the signal coming from the process $e^+e^-\to V \to tc$ ($V=Z,\,Z^{\prime}$) provide a detectable signal and thus it can give evidence for FCNC interactions; in these scenarios the mass of a new neutral gauge boson can be as high as $m_{Z'}=7$ TeV.

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arXiv2020

Flavor-changing decay $h\to τμ$ at super hadron colliders

We study the flavor-changing decay $h\to τμ$ with $τ=τ^-+τ^+$ and $μ=μ^-+μ^+$ of a Higgs boson at future hadron colliders, namely: a) High Luminosity Large Hadron Collider, b) High Energy Large Hadron Collider and c) Future hadron-hadron Circular Collider. The theoretical framework adopted is the Two-Higgs-Doublet Model type III. The free model parameters involved in the calculation are constrained through Higgs boson data, Lepton Flavor Violating processes and the muon anomalous magnetic dipole moment; later they are used to analyze the branching ratio of the decay $h\toτμ$ and to evaluate the $gg\to h$ production cross section. We find that at the Large Hadron Collider is not possible to claim for evidence of the decay $h\toτμ$ achieving a signal significance about of $1.46σ$ by considering its final integrated luminosity, 300 fb$^{-1}$. More promising results arise at the High Luminosity Large Hadron Collider in which a prediction of 4.6$σ$ when an integrated luminosity of 3 ab$^{-1}$ and $\tanβ=8$ are achieved. Meanwhile, at the High Energy Large Hadron Collider (Future hadron-hadron Circular Collider) a potential discovery could be claimed with a signal significance around $5.04σ$ ($5.43σ$) for an integrated luminosity of 3 ab$^{-1}$ and $\tanβ=8$ (5 ab$^{-1}$ and $\tanβ=4$).

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arXiv2019

Search for the $t\to ch$ decay at hadron colliders

We study the observability for the flavor-changing decay of a top quark $t\to ch$ at the LHC and future hadron colliders, namely, High-Luminosity LHC (HL-LHC), High-Energy LHC (HE-LHC) and Future Circular hadron-hadron Collider (FCC-hh). Two scenarios in which the Higgs boson could decay: into a quark bottom pair $(\textit{bb-channel})$ and two photons $(\textit{$γγ$-channel})$ are analyzed. A Monte Carlo analysis of the signal and the Standard Model (SM) background is computed. Center-of-mass energies of $\sqrt{s}=14,\;27\; $\text{and}$\; 100$ TeV and integrated luminosities from $0.3$ to $30$ ab$^{-1}$ are explored. The theoretical framework adopted in this work is the Type-III Two-Higgs Doublet Model (THDM-III) for which, constraints on the parameter space from the Higgs boson coupling modifiers $κ_i$ are presented and used in order to evaluate the branching ratio of the $t\to ch$ decay and the ($pp\to t\bar{t},\,t\to ch$) production cross section. We find that with the integrated luminosity achieved at the LHC, the $t\to ch$ decay is out of the reach of detection. More promising results emerge for the HL-LHC, HE-LHC and FCC-hh in which potential discoveries could be claimed.

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