Searcharxiv⌕ Search

arXiv subjects

M. A. Arroyo-Ureña

Publications and source records attributed to M. A. Arroyo-Ureña.

At least 19 recordsLinked to original sources

Fermion mass hierarchy and flavor signals from a $D_4$ dihedral symmetry within a 2HDM-Tx with four-zero textures

We propose an extended Texturized Two-Higgs Doublet Model (2HDM-Tx) where a discrete $D_4$ symmetry predicts a four-zero texture in the fermion mass matrices. In contrast to the standard ansatz where the underlying Yukawa matrices are assumed to be structurally identical, we introduce a novel configuration of non-equivalent matrices that complementarily generate a specific Hermitian four-zero mass structure. This framework naturally suppresses flavor-changing neutral currents and provides a structural rationale for the fermion mass hierarchy, while in addition including a dark matter candidate. As a concrete phenomenological application, we show that the model simultaneously accommodates the persistent neutral resonance excesses at $95\text{ GeV}$ and $152\text{ GeV}$, satisfies current \text{LHC} Higgs data, and is consistent with the stringent upper bounds from lepton flavor violation processes. These combined constraints severely restrict the parameter space of the scalar phenomenology. Finally, we study the prospects for the discovery of the lepton-flavor violating process $h \to τμ$ at the High-Luminosity LHC.

hep-ph↗

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.

hep-ph↗

The $Z_3$ soft breaking in the I(2+1)HDM and its cosmological probes

A $ Z_3 $ symmetric 3-Higgs Doublet Model (3HDM) with two inert doublets and one active doublet (which plays the role of the Higgs doublet), the so-called I(2+1)HDM, is studied. We discuss the behaviour of this 3HDM realisation when one allows for a $ Z_3 $ soft-breaking term. In this setup, the lightest $Z_3$ charged neutral scalar can be a Dark Matter (DM) candidate. If the breaking scale is small enough, this model provides a long-lived neutral state with the opposite CP parity to the DM state. This long-lived particle could then be another effective DM candidate when its lifetime is comparable to the age of the universe. In this case, we have studied the properties of the ensuing relic density in the presence of the most recent limits from direct searches for DM. Conversely, the case in which the long-lived particle actually decays into the DM particle and Standard Model particles in a detector at a collider experiment is very attractive from the viewpoint of phenomenology. Under such conditions, we have studied signatures involving missing transverse energy and multiple leptons (and jets) at the International Linear Collider (ILC) in the presence of displaced vertices.

hep-ph↗

Lepton flavor violation in Higgs boson decays at the HL-LHC

We explore the discovery potential for lepton flavor-violating Higgs boson decays, $h \to \ell_i \ell_j$ ($\ell_i \neq \ell_j$; $\ell = e, μ, τ$), in proton-proton collisions. The analysis is performed within a Froggatt-Nielsen framework, which offers a well-motivated theoretical mechanism for such processes. By performing a systematic scan over the phenomenologically viable parameter space, we identify regions that can yield observable signatures at the High-Luminosity LHC (HL-LHC). For an integrated luminosity of $\mathcal{L}_{\rm int} \gtrsim 1000~\text{fb}^{-1}$, we project that the channels $h \to eμ$ and $h \to τμ$ (with $τ^{\pm} \to π^{\pm} ν_τ$) could reach the $5σ$ discovery threshold, while $h \to τe$ remains inaccessible even at $3000~\text{fb}^{-1}$. Our results highlight the unique capability of the HL-LHC to probe new physics through searches for rare Higgs decays.

hep-ph↗

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.

hep-ph↗

Searching for the LFV $γγeμ$ interaction at future $e^- e^+$ colliders

We investigate the Lepton Flavor Violating (LFV) process $e^{+}e^{-}\to e^{+}e^{-}eμ$ ($e=e^-,\,e^+,\,μ=μ^-,\,μ^+ $) at future circular colliders, probing the effective $γγeμ$ interaction through photon fusion. Within an Effective Field Theory (EFT) framework compatible with theoretical and experimental constraints, we identify regions in the parameter space of the effective couplings where the signal could be observed at the Circular Electron-Positron Collider (CEPC) at $\sqrt{s}=240\ \text{GeV}$ and the Future Circular Collider (FCC-ee) at $\sqrt{s}=240$ and $350\ \text{GeV}$. Our analysis leverages distinctive kinematic distributions -- particularly the transverse momentum of the scattered electron $p_{T}^{(e^{-}\ \text{scattered})}$ and the central muon $p_{T}^μ$ -- to achieve efficient signal-background separation. By employing a neural network classifier, we enhance the sensitivity beyond traditional cut-based methods, demonstrating the discovery potential of these facilities for LFV searches in the clean environment of $e^{+}e^{-}$ collisions.

hep-ph↗

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.

hep-ph↗

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 $\mathcal{BR}(t\to ch)$.

hep-ph↗

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$^{-1}$.

hep-ph↗

Prospects for detecting the rare heavy Higgs decay $H\to hγγ$ through the $H\to b\bar{b}γγ$ channel at the LHC

We study the decay of a heavy CP-even neutral Higgs into an on-shell Standard Model-like Higgs boson and two photons, $H\to hγγ$, in the two-Higgs doublet model. We argue that the decay channel $H\to hγγ$, followed by the decay of the Standard Model Higgs $h\rightarrow b\bar b$, could be observed at the 5$σ$ level at the High-Luminosity LHC for masses of the heavy Higgs up to 950 GeV for the type-II, 650 GeV for the Lepton Specific and the Flipped 2HDMs, and 350 GeV for the type-I. We also discuss the possible role of the decay $H\to hγγ$ in discriminating among different types of 2HDMs and in enhancing the total number of events in the final state $H\rightarrow b\bar b γγ$ compared to the cascade decay $H\to hh$ followed by $h\toγγ$ $h\to b\bar{b}$ with identical final state (although with different kinematical distributions).

hep-ph↗

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$^{-1}$.

hep-ph↗

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.

hep-ph↗

Hunting a charged Higgs boson pair in proton-proton collisions

We explore the production and possible detection of a charged scalar Higgs pair $H^-H^+$ decaying into the final state $μν_μcb$ in proton-proton collisions at the LHC and its next step, the High Luminosity LHC (HL-LHC). The charged scalars are predicted within the theoretical framework of the Two-Higgs Doublet Model of type III (2HDM-III). As a test and validation of the model, we identify regions of the 2HDM-III parameter space that accommodate the current excess of events at $3σ$ in the process $\mathcal{BR}(t\to H^{\pm}b)\times \mathcal{BR}(H^{\pm}\to cb)$ for $M_{H^{\pm}}=130$ GeV, as reported by the ATLAS collaboration. Theoretical and additional experimental constraints are also included. Based on this, we propose realistic scenarios that could be brought under experimental scrutiny at the HL-LHC. Assuming the most favorable scenario, we predict a signal significance at the level of $5σ$ for a charged scalar boson mass $M_{H^{\pm}}$ in the $100-350$ GeV range.

hep-ph↗

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.

hep-ph↗

$\texttt{SpaceMath v.2.0}$ 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.

hep-ph↗

Flavor changing Flavon decay $ϕ\to tc$ ($ϕ=H_F,\,A_F$) at the High Luminosity Large Hadron Collider

We present a study of the flavor changing decays $ϕ\to tc$ ($ϕ=H_F,\,A_F$) of the $CP$-even and $CP$-odd scalar flavons at the large hadron collider and its next stage, the high-luminosity large hadron collider. The theoretical framework is an extension of the standard model that incorporates an extra complex singlet and invokes the Froggatt-Nielsen mechanism with an Abelian flavor symmetry. The projected exclusion and discovery regions in terms of the model parameters are reported. We find that $A_F$ could be detected at the LHC by considering a reasonable scenario of the model parameter space. As far as $H_F$ is concerned, we also found promising results that could be verified experimentally at the high-luminosity LHC.

hep-ph↗

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.

hep-ph↗

One-loop determination of $τ\to π(K) ν_τ[γ]$ branching ratios and new physics tests

We calculate the ratios $R_{τ/ P}\equiv Γ\left( τ\to P ν_τ[γ] \right) / Γ\left(P\to μν_μ[γ]\right)$ ($P=π,K$) at one loop following a large-$N_C$ expansion where Chiral Perturbation Theory is enlarged by including the lightest resonances and respecting the short-distance behavior dictated by QCD. We find $δR_{τ/π}=(0.18\pm 0.57 )\%$ and $δR_{τ/K}=(0.97\pm 0.58 )\%$, where the uncertainties are induced fundamentally by the counterterms. We test the lepton universality, obtaining $\left|g_τ/g_μ\right|_π=0.9964\pm 0.0038$ and $\left|g_τ/g_μ\right|_K=0.9857\pm 0.0078$, and analyze the CKM unitarity, getting results at $2.1σ$ and $1.5σ$ from unitarity via $|V_{us}/V_{ud}|$ and $|V_{us}|$, respectively. We also update the search for non-standard interactions in $τ$ decays. As a by-product, we report the theoretical radiative corrections to the $τ\to P ν_τ[γ]$ decay rates: $δ_{τπ} = -(0.24 \pm 0.56) \%$ and $δ_{τK} = -(0.15 \pm 0.57) \%$.} \maketitle

hep-ph↗