arXiv subjects

A. Arhrib

Publications and source records attributed to A. Arhrib.

At least 19 recordsLinked to original sources

arXiv2026

VLQBounds: Confronting Vector-Like Quark Models with LHC Searches

We present VLQBounds, a public, data-driven Python framework for testing Vector-Like Quark (VLQ) scenarios against Large Hadron Collider (LHC) exclusion limits from ATLAS and CMS. The framework incorporates public results on both pair and single VLQ production and supports the main parameterisations used in experimental interpretations, including mass-mixing, mass-coupling, and mass-width representations. For each parameter point, the predicted cross-section or effective coupling is compared channel by channel to the corresponding observed and expected experimental limits through interpolation over machine-readable grids. The most sensitive analysis is automatically identified and a 95\% Confidence-Level exclusion verdict is returned, together with the observed and expected sensitivity ratios and the metadata needed for reproducible reinterpretation. The modular structure of VLQBounds makes it suitable for fast phenomenological scans, validation of public limits, and future extensions to new collider searches and non-minimal VLQ decay patterns.

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arXiv2025

Analysis of the $ q\bar q\to Z^* \to hA \to4\tau$ process within the lepton-specific 2HDM at the LHC

We analyse light Higgs scalar and pseudoscalar associated hadro-production in the 2-Higgs Doublet Model (2HDM) Type-X (or lepton-specific) within the parameter space allowed by theoretical self-consistency requirements as well as the latest experimental constraints from the Large Hadron Collider (LHC), precision data and $B$ physics. Over the viable regions of such a scenario, the Standard Model-like Higgs boson discovered at the LHC in 2012 is the heavier CP-even state $H$. Furthermore, in the Type-X scenario, due to large $\tan\beta$, the lighter Higgs scalar $h$ and the pseudoscalar $A$ mainly decay into two $\tau$ leptons. Therefore, we concentrate on analysing the signal process $pp\to Z^{*} \to hA\to \tau^{+}\tau^{-}\tau^{+}\tau^{-}\to \ell \nu_\ell \ell \nu_\ell \tau_h \tau_h$ (where $\ell= e, \mu$ whereas $\tau_h$ represents the hadronic decay of the $\tau$) and explore the feasibility of conducting such a search at the LHC with a centre-of-mass energy of $\sqrt{s}~=$ 14 TeV and a luminosity of $L~=~300~fb^{-1}$. To suppress the huge SM background, we confine ourselves to consider the fraction of signal events with two same-sign $\tau$ leptons further decaying into same-sign leptons while the other two $\tau$ leptons decay hadronically. We find that a combination of kinematical selection and machine learning (ML) analysis will yields significant sensitivity to this process at the end of the LHC Run 3.

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arXiv2024

Probing a 2HDM Type-I light Higgs state via $H_{\rm SM} \to hh \to b\bar bγγ$ at the LHC

We study the discovery potential for a light Higgs boson via $gg \to H_{\text{SM-like}} \to hh \to b\bar{b}γγ$ process at the Large Hadron Collider (LHC). Focusing on the 2-Higgs Doublet Model (2HDM) Type-I, which can accommodate light neutral Higgs states, of $\mathcal{O}(100)$ GeV or less in mass, while agreeing with theoretical and up-to-date experimental constraints, we explore the feasibility of a light CP-even Higgs state $h$ via the largely unexplored final state $b\bar{b}γγ$ at Run-3 of the LHC. We further propose a few Benchmark Points (BPs) for future searches.

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arXiv2024

Probing a light Higgs in $ H \to hh \to b\bar{b}ττ$ in Type-I 2HDM at the LHC

In this study, we explore the potential to probe the process $gg \to H_{\text{SM-like}} \to hh \to b\bar{b}ττ$ at the Large Hadron Collider (LHC), within the framework of the Two Higgs Doublet Model (2HDM) Type-I. After performing a detailed Monte Carlo (MC) simulation, we focus on isolating the signal from the Standard Model (SM) backgrounds. Our analysis employs a dedicated trigger choice and optimised kinematic selection to improve the signal sensitivity. We demonstrate some sensitivity to this decay channel at Run 3, while the High-Luminosity LHC (HL-LHC) can provide discovery evidence.

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arXiv2024

Analysis of the $gg\to H\to hh\to4τ$ process in the 2HDM lepton specific model at the LHC

We analyse the signature of a light Higgs boson pair in the 2-Higgs Doublet Model(2HDM) Type-X (or lepton specific) over the parameter spaces allowed by theoretical self-consistency requirements as well as the latest experimental constraints from the Large Hadron Collider (LHC), precision test data and $B$ physics. Over the viable regions of the latter, wherein the Standard Model (SM)-like Higgs boson discovered at the LHC in 2012 is the heavier CP-even state of the 2HDM, $H$, it is found that the SM-like Higgs boson can decay into a pair of the lighter CP-even Higgs boson, $h$, via the process $H\to hh$ with a Branching Ratio (BR) of $5\%-10\%$ or so, (with $2 m_h < m_H =125$ GeV). Furthermore, in the Type-X scenario, the lighter Higgs bosons $h$ can dominantly decay into two $τ$'s due to a large $\tanβ$. Therefore, the pair of lighter Higgs bosons can altogether decay into a 4 $τ$ final state. In order to suppress the huge SM background events, we confine ourself to consider the fraction of signal events with two Same-Sign (SS) $τ$'s further decaying into same sign leptons while the other two $τ$'s decay hadronically. By using Monte Carlo (MC) and Machine Learning (ML) tools, we thus focus on the analysis of the signal process $pp\to H\to hh\to τ^{+}τ^{-}τ^{+}τ^{-}\to \ell v_\ell \ell v_\ell τ_h τ_h$ (where $\ell= e, μ$ and $τ_h$ means a hadronic decay of the $τ$) and explore the feasibility of such a search at the LHC for a collision energy $\sqrt{s}=~\text{14 TeV}$ and a luminosity $\text{300}~\text{fb}^{-1}$

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arXiv2023

Probing a light charged Higgs boson at the LHC Run 3

We study the Large Hadron Collider (LHC) discovery prospects of a light charged Higgs boson decaying into a $W$ boson and a non-Standard Model (SM)-like Higgs within the 2-Higgs Doublet Model type-I. In the analysis, we consider the associated production of a charged Higgs boson with a light neutral one, $pp \rightarrow H^{\pm} h$, with the subsequent $H^\pm \rightarrow W^{\pm*} h$. We then investigate the emerging $W^{\pm*} + 4b$ final state and provide several benchmark points for signal-to-background analysis. We therefore show that this signal could be an excellent avenue for identifying $H^\pm$ at the LHC.

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arXiv2023

Searching for $H \to hh \to b\bar bττ$ in the 2HDM Type-I at the LHC

Unlike other realisations of the 2-Higgs Doublet Model (2HDM), the so-called Type-I allows for a very light Higgs boson spectrum. Specifically, herein, the heaviest of the two CP-even neutral Higgs states, $H$, can be the one discovered at the Large Hadron Collider (LHC) in 2012, with a mass of $\approx 125$ GeV and couplings consistent with those predicted by the Standard Model (SM). In such a condition of the model, referred to as `inverted mass hierarchy', the decay of the SM-like Higgs state into pairs of the lightest CP-even neutral Higgs boson, $h$, is possible, for masses of the latter ranging from $M_H/2\approx 65$ GeV down to 15 GeV or so, all compatible with experimental constraints. In this paper, we investigate the scope of the LHC in accessing the process $gg\to H \to hh\to b\bar bττ$ by performing a Monte Carlo (MC) analysis aimed at extracting this signal from the SM backgrounds, in presence of a dedicated trigger choice and kinematic selection. We prove that some sensitivity to such a channel exists already at Run 3 of the LHC while the High-Luminosity LHC (HL-LHC) will be able to either confirm or disprove this theoretical scenario over sizable regions of its parameter space.

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arXiv2023

Discovering a light charged Higgs boson via $W^{\pm *}$ + 4$b$ final states at the LHC

Most of the current experimental searches for charged Higgs bosons at the Large Hadron Collider (LHC) concentrate upon the $tb$ and $τν$ decay channels. In the present study, we analyze instead the feasibility of the bosonic decay channel $W^{\pm *} h$, with the charged gauge boson being off-shell and $h$ being a neutral light Higgs boson, which decays predominantly into $b\bar{b}$. We perform a Monte Carlo (MC) analysis for the associate production of a charged Higgs with such a light neutral one, $pp\to H^\pm h$, at the LHC followed by the aforementioned charged Higgs boson decay, which leads to a $W^{\pm *} +4b$ final state. The analysis is performed within the 2-Higgs Doublet Model (2HDM) with Yukawa texture of Type-I. We take into account all available experimental constraints from LEP, Tevatron and the LHC as well as the theoretical requirements of self-consistency of this scenario. In order to study the full process $pp \rightarrow H^{\pm} h \rightarrow W^{\pm *} h h \rightarrow \ell^\pm ν+ 4b$ ($\ell=e,μ$), we provide several Benchmark Points (BPs) amenable to further analysis, with $M_{H^\pm}+M_{b} < M_{t}$, for which we prove that there is a strong possibility that this spectacular signal could be found at the LHC with center of mass energy 14 TeV and luminosity 300 $\rm{fb}^{-1}$.

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arXiv2023

Single-charged Higgs boson in $W^\pm H^\mp$ associated production within the 2HDMs

In this contribution, the likelihood of seeing charged Higgs and $W$ boson production in the context of 2HDMs type-I and type-X at the LHC is examined, assuming that either $h$ or $H$ resembles the detected resonance around $\sim 125$ GeV. We consider the possibility of the charged Higgs boson decays channels through $H^\pm \to W^\pm h_i / A$, focusing on the $b\bar{b}$ and $ττ$ decays of $h_i$ and $A$. In both type-I and type-X insights of the 2HDMs, we investigate the potential fingerprints resulting from the previously mentioned charged Higgs production and decay. We find in our study that these signatures can have sizable rates at low $\tanβ$ as long as the condition $M_{H^\pm} < m_t - m_b$ is met. As a result, we propose the $bb$ and $ττ$ final states associated with $WW$ as an encouraging experimental avenue that would complement the LHC search for a charged Higgs boson.

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arXiv2022

Single charged Higgs boson production at the LHC

A search for charged Higgs may yield clear and direct signs of new physics outside the realm of the Standard Model (SM). In the Two-Higgs Doublet Model (2HDM), we investigate two of the main single charged Higgs production channels at the Large Hadron Collider (LHC), assuming that either $h$ or $H$ replicates the detected resonance at $\sim 125~\rm{GeV}$. We consider the possibility of the charged Higgs boson production through the $pp \rightarrow H^\pm W^\mp$ and $pp \rightarrow H^\pm bj$ production processes that may present additional significance at the LHC experiments. Considering the $H^\pm \rightarrow W^\pm h_i/A$ decay channels and mainly concentrating on the $b\bar{b}$, $ττ$ and $γγ$ decays of $h_i$ and $A$, we examine the possible signatures arising from the aforementioned charged Higgs production and decay in both type-I and type-X realizations of 2HDM. Our study shows that these signatures can have sizable rates at low $\tanβ$ as long as the condition $M_{H^\pm} < m_t - m_b$ is satisfied. As a result, we propose the $bb$, $ττ$ and $γγ$ final states associated with $WW$ or $Wbj$ as an encouraging experimental avenue that would complement the LHC search for a charged Higgs boson.

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arXiv2022

Light charged Higgs boson in $H^\pm h$ associated production at the LHC

We investigate the light charged Higgs boson production via $pp \rightarrow H^\pm h$ at the Large Hadron Collider (LHC) in the Two-Higgs Doublet Model (2HDM) type-I. By focusing on a scenario where $H$ is the observed Higgs boson of mass 125 GeV, we study the aforementioned Higgs boson production channel and explore its bosonic decay $H^\pm \rightarrow W^\pm h$. The latter can have a sizable rate that possibly dominates, over the fermionic decay channels, in several regions of the viable parameter space. We demonstrate that the production process $pp \rightarrow H^\pm h$ followed by $H^\pm \rightarrow W^\pm h$ could be the most promising experimental avenue to search for light $H^\pm$ at the LHC.

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arXiv2022

Is the new CDF $M_W$ measurement consistent with the two higgs doublet model?

Motivated by the new CDF measurement of the $W$ boson mass reported recently which clearly illustrates a large deviation compared to the Standard Model (SM) prediction. In the present paper, we study the Two-Higgs Doublet Model (2HDM) contributions to $M_W$ and its phenomenological implications in the case where the heavy CP-even $H$ is identified as the observed Higgs boson with a mass of $125$ GeV. Taking into account theoretical and all the available experimental constraints as well as the new CDF measurement, we demonstrate that the 2HDM parameter space can provide a large correction which predicts the W mass close to the new CDF $M_W$ measurement. It is found that $M_{H\pm}=M_A$ is excluded and the splitting of the charged Higgs boson with all other states is positive. We also discuss the consequence on the effective mixing angle $\sin^2θ_{\text{eff}}$ as well as the phenomenological implications on the charged Higgs and CP-odd decays.

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arXiv2021

New Discovery Modes for a Light Charged Higgs Boson at the LHC

At the Large Hadron Collider (LHC), both the ATLAS and CMS Collaborations have been searching for light charged Higgs bosons via top (anti)quark production and decays channels, like $pp\to t \bar{t}$ with one top (anti)quark decaying into a charged Higgs boson and a $b$ (anti)quark, when the decay is kinematically open (i.e., when $m_{H^\pm}\lesssim m_t$). In this paper, we propose new searches at the LHC involving light charged Higgs bosons via their pair production channels like $pp\to H^\pm h/A$ and $pp\to H^+ H^-$ in the 2-Higgs Doublet Model (2HDM) Type-I and -X scenarios. By focusing on the case where the heavy $H$ state plays the role of the Standard Model (SM)-like Higgs boson with a mass near 125 GeV, we study the aforementioned Higgs boson pair production channels and investigate their bosonic decays, such as $H^\pm \to W^{\pm } h$ and/or $H^\pm \to W^{\pm } A$. We demonstrate that for a light charged Higgs boson state, with $m_{H^\pm}\lesssim m_t$, at the LHC, such di-Higgs production and decay channels can give rise to signatures with event rates much larger than those emerging from $pp\to t\bar{t}\to t\bar{b} H^-$ + c.c.. We specifically study $h/A\to b\bar b$ and $τ^+τ^-$ decays. We, therefore, claim that the discussed combination of new production and decay modes can result in an alternative discovery channel for charged Higgs bosons lighter than the top (anti)quark at the LHC within the above two 2HDM Types. Finally, in order to motivate experimentalists in ATLAS and CMS to search for such signatures, we propose 16 Benchmark Points (BPs) which are compatible with both theoretical and experimental constraints.

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arXiv2021

Searching for $H^\pm\to W^{\pm} + 4γ$ signals in the 2HDM Type-I at the LHC

We analyze a new signature of a charged Higgs boson in the Type-I realization of the 2-Higgs Doublet Model (2HDM), where the mass of the charged Higgs boson satisfies the condition $M_{H^{\pm}}<M_{t}+M_{b}$ and the theoretical parameter space is consistent with the latest experimental constraints from Large Hadron Collider (LHC) and other direct as well as indirect searches. In the surviving regions, it is found that the bosonic decay mode of a charged Higgs boson is dominated by $H^{\pm} \rightarrow W^{\pm*}h$. At the same time, the light neutral Higgs boson $h$ dominantly decays into two photons. We thus find that the production process $pp \rightarrow H^{\pm}h \rightarrow W^{\pm*}h h \rightarrow l^{\pm}ν+4γ$ is almost background free. Since the $W^{\pm}$ could be either off-shell or on-shell, furthering a previous phenomenological analysis, we examine closely detector effects onto the above signature and demonstrate that it is indeed promising to study it at the LHC with both $\sqrt{s}= 13$ TeV and $\sqrt{s} = 14$ TeV, assuming an integrated luminosity of 300 $fb^{-1}$.

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arXiv2021

Analysis of $W^\pm+4γ$ in the 2HDM Type-I at the LHC

We analyse a light charged Higgs boson in the 2-Higgs Doublet Model (2HDM) Type-I, when its mass satisfies the condition $M_{H^{\pm}} < M_{t}+M_{b}$ and the parameter space is consistent with theoretical requirements of self-consistency as well as the latest experimental constraints from Large Hadron Collider (LHC) and other data. Over such a parameter space, wherein the Standard Model (SM)-like state discovered at the LHC in 2012 is the heaviest CP-even state of the 2HDM, it is found that the decay modes of the charged Higgs boson are dominated by $H^{\pm} \rightarrow W^{\pm *} h$. Furthermore, the light neutral Higgs boson $h$ dominantly decays into two photons. Under these conditions, we find that the production and decay process $ p p \to H^\pm h \to {W^\pm}^{(*)} h h \to l ν_{l} + 4 γ$ ($l=e,μ$) is essentially background free. However, since the $W^{\pm(*)}$ could be largely off-shell and the $h$ state is very light, so that both the lepton coming from the former and the photons coming from the latter could be rather soft, we perform here a full Monte Carlo (MC) analysis at the detector level demonstrating that such a $W^{\pm} + 4γ$ signal is very promising, as it would be yielding significant excesses at the LHC with an integrated luminosity of $L=$ 300 $fb^{-1}$ at both $\sqrt{s}= 13$ and $14 ~\text{TeV}$.

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arXiv2019

Associated production of SM Higgs with a photon in type-II seesaw models at the ILC

We consider the production of a single Standard Model (SM) Higgs boson ($h^0$) in association with a photon at the future Linear collider (LC) in the context of a type-II seesaw model. The type-II seesaw model extends the SM particle content by adding one triple Higgs where its Higgs coupling is a key parameter of the scalar potential triggering the electroweak symmetry-breaking mechanism in the SM. It is a well motivated model since it provides neutrino masses and mixing. The LC presents a particularly interesting possibility to probe Higgs couplings due to the clean beams in the initial state. We study the one loop processes $e^+e^- \to h^0γ$ and $e^-γ\to e^- h^0$, we show that it is possible to correlate the total cross section predictions with the couplings $h^0γγ$ and $h^0γZ$ which are sensitive to the presence of singly and doubly charged Higgs. For parameter points allowed by the current experimental constraints, our numerical results show that the effect of $H^\pm$ and $H^{\pm\pm}$ can be as large as $\pm$ 25\% with respect to the SM predictions. For both processes, we also present differential cross section for different center of mass energy.

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arXiv2019

The two-real-singlet Dark Matter model

We revisit a Dark Matter model with an extension of the Standard Model with two real singlets $χ$ and $η$ obeying a $Z_2 \otimes Z_2'$ symmetry, where $Z_2'$ is broken spontaneously. While $χ$ serves as a stable Dark Matter candidate providing the relic density, the real $η$ field plays the role of a light mediator. We study the viability of this model with respect to Dark Matter self-interactions which may explain the density profiles observed in dwarf galaxies up to scales of the size of our Milky Way. Moreover, the Standard Model-like Higgs boson of the model has a tiny mixing with the mediator field and appears to be consistent with current LHC data. In this rather minimal extension of the Standard Model the mediator $η$ decays naturally into Majorana neutrinos neither disturbing standard big bang nucleosynthesis nor cosmic microwave background observations.

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arXiv2018

Extended Higgs sector of 2HDM with real singlet facing LHC data

We study the phenomenology of the two Higgs doublet model with a real singlet scalar $S$ (2HDMS). The model predicts three CP-even Higgses $h_{1,2,3}$, one CP-odd $A^0$ and a pair of charged Higgs. We discuss the consistency of the 2HDMS with theoretical as well as with all available experimental data. In contrast with previous studies, we focus on the scenario where $h_2$ is the Standard Model (SM) 125 GeV Higgs, while $h_1$ is lighter than $h_2$ which may open a window for Higgs to Higgs decays. We perform an extensive scan into the parameter space of 2HDMS of type I and explore the effect of the singlet-doublet admixture. We found that a large singlet-doublet admixture is still compatible with the recent Higgs data from LHC. Moreover, we show that $h_1$ could be quasi-fermiophobic and would decay dominantly into two photons. We also study in details the consistency of the non-detected decay of $h_2\to h_1 h_1$ with LHC data followed by $h_1\to γγ$ which leads to four photons final state at LHC: $pp\to h_2\to h_1 h_1\to 4γ$. Using the results of null searches of multi-photons carried by the ATLAS collaboration, we have found that a large area of the parameter space is still allowed. We also demonstrate that various neutral Higgs of the 2HDMS could have several exotic decays.

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