arXiv subjects

Mohamed Krab

Publications and source records attributed to Mohamed Krab.

12 recordsLinked to original sources

arXiv2026

Dark Matter in the General 2HDM with Extra Top Yukawa Couplings

We extend the general two Higgs doublet model (G2HDM), which introduces extra Yukawa couplings, by an additional real scalar singlet (G2HDM+S), providing a viable scalar dark matter (DM) candidate. This setup provide a viable UV completion of top-window dark matter scenarios, in which DM communicates with the standard model predominantly through the top quark. We analyze the constraints on the visible scalar sector from Higgs signal strength measurements and direct searches for additional Higgs bosons at the LHC, and those on the dark sector from cosmological observables, including the observed DM relic density and spin-independent direct-detection as well as indirect detection. Within the surviving parameter space, we identify a rich and diverse LHC phenomenology governed by the interplay between the singlet portal, the extended Yukawa sector, and the heavy scalar mass hierarchy. To facilitate experimental investigation, we propose six benchmark scenarios spanning the singlet-portal, bosonic-cascade, fermiophilic, and flavor-violating regimes. In the latter, the nondiagonal top-charm coupling $\rho_{tc}$ induces the production channel $cg \to tH$, allowing the top quark to serve as a trigger for an otherwise invisible $H\to SS$ signal. This flavor-violating DM production is a distinct feature of the G2HDM+S.

hep-ph↗

arXiv2026

Possibility of Probing an Extra Higgs Boson at the Compact Linear Collider

We study the sensitivity of the Compact Linear Collider (CLIC) to an additional neutral Higgs boson $H$ through the vector boson fusion process $e^+e^- \to H\nu\bar \nu$, followed by the decay $H \to W^+W^-$, with both $W$ bosons decaying leptonically, resulting in a dilepton plus missing transverse energy final state. Within the framework of the Two Higgs Doublet Model, where both production and decay are governed by the Higgs mixing angle $\cos(\beta-\alpha)$, we perform a detector-level analysis and show that a high-energy CLIC can probe $H$ via this channel, allowing a direct measurement of the $HWW$ coupling.

hep-ph↗

arXiv2025

Enhanced Charged Higgs Signal at the LHC

We investigate the discovery prospects of a charged Higgs boson ($H^\pm$) at the Large Hadron Collider (LHC) via the process $cg\to bH^\pm \to bc\bar{b}$ within the framework of a general two Higgs doublet model (G2HDM). In most two Higgs doublet models, the $H^+ cb$ coupling ($g_{H^+cb}$) is usually suppressed by the CKM matrix element $V_{cb}$. In G2HDM, there are additional Yukawa couplings, the process $cg\to bH^\pm \to bc\bar{b}$ is enhanced by the coupling $g_{H^+cb} \simeq \rtc V_{tb}$ in both the production and decay of the charged Higgs boson. We study possible physics backgrounds and evaluate the discovery potential with realistic acceptance cuts and tagging efficiencies at collider energies of $\sqrt{s}=$13 and 14 TeV. We apply $b$-tagging and $c$-tagging and show that $m_{H^+}$ can be extracted by pairing the tagged $b$ and $c$-jets. Our analysis leads to promising results for the current LHC and expected high-luminosity LHC.

hep-ph↗

arXiv2025

Probing an extra Higgs boson at future linear $e^+ e^-$ colliders

We investigate the possibility of probing an extra Higgs boson at future linear $e^+ e^-$ colliders. We consider the production process $e^+e^- \to H\nu \bar\nu$, followed by the decay $H \to W^+W^-$, where $H$ is the extra $\textit{CP}$-even Higgs boson of the general two Higgs doublet model (G2HDM). This process is governed by the $\textit{CP}$-even Higgs mixing angle, $\cos\gamma$, offering direct access to this parameter. We discuss constraints on $\cos\gamma$ using existing LHC data and test the viability of the G2HDM top-quark-driven scenario for electroweak baryogenesis. We perform a full Monte Carlo simulation of the signal and background, and show that an extra Higgs boson in the mass range $200 \leq m_H \leq 400$ GeV could be probed at high energy linear $e^+ e^-$ colliders. Promising results are found for CLIC running at 1.5 and 3 TeV collision energies.

hep-ph↗

arXiv2025

Searching for charged Higgs bosons with flavor-changing couplings at the LHC

We investigate the LHC discovery prospects for charged Higgs bosons in the general two Higgs doublet model (G2HDM) that has flavor-changing neutral Higgs (FCNH) couplings. The FCNH $\rho_{tc}$ coupling induces intriguing $H^+$ production processes $c\bar b \to H^+$, $cg \to bH^+$, and $\bar bg \to \bar cH^+$ without CKM suppression. Sizable $\rho_{tc}$ can drive the disappearance of antimatter from the Universe. In this contribution, we promote the resonant $c\bar b \to H^+$ production, followed by the bosonic $H^+ \to W^+ H$ decay. Discovery could be a harbinger of G2HDM with FCNH couplings, and perhaps shed light on the baryon asymmetry of the Universe.

hep-ph↗

arXiv2025

Searching for charged Higgs bosons via $e^+ e^- \to H^\pm W^\mp S$ at the ILC

We investigate the phenomenology of the charged Higgs boson at the International Linear Collider (ILC) within the framework of the type-X Two-Higgs Doublet Model (2HDM), where a light charged Higgs boson, with a mass around 200 GeV or even smaller than top quark mass, is still being consistent with flavor physics data as well as with the colliders experimental data. In the theoretically and experimentally allowed parameter space, the $e^+ e^- \to H^\pm W^\mp S$ (with $S = H, A$) production processes can yield signatures with event rates larger than those from $e^+ e^- \to H^+ H^-$ and offer sensitivity to the Higgs mixing parameter $\sin(\beta-\alpha)$. We consider the bosonic $H^\pm \to W^\pm S$ decays, where the neutral scalar $S$ further decays into a pair of tau leptons. We show, through a detector-level Monte Carlo analysis, that the resulting $[\tau\tau][\tau\tau] WW$ final state could be seen at the ILC with at least 500 GeV center-of-mass energy and 500 fb$^{-1}$ of luminosity.

hep-ph↗

arXiv2025

Probing the general 2HDM with flavor violation through $A \to ZH$

We investigate the LHC discovery prospects for a second Higgs doublet through $A \to ZH$ weak decay. The latter is identified as the $\textit{smoking gun signature}$ of two Higgs doublet models (2HDMs) with first-order electroweak (EW) phase transition, a necessary condition for EW baryogenesis. In the general 2HDM (G2HDM) that has flavor-changing neutral Higgs couplings, $H$ may decay dominantly via $t\bar c + \bar tc$ final states, giving rise to trilepton signals. By a phenomenological analysis, we show that $A \to ZH$ in $\ell^+ \ell^- t\bar c$ or $\ell^+ \ell^- \bar t c$ final states could be a promising probe of G2HDM at the LHC with flavor violation.

hep-ph↗

arXiv2025

Searching for resonant flavor-changing charged Higgs production at the LHC

We suggest a resonant $c \bar b \to H^+$ production search, followed by bosonic $H^+ \to W^+ H$ weak decay at the Large Hadron Collider (LHC). In the general two-Higgs-doublet model (G2HDM) that has flavor-changing neutral Higgs couplings, $H^+$ is resonantly produced via the top-charm $ρ_{tc} V_{tb}$ coupling at tree level, while $H^+ \to W^+ H$ weak decay occurs within the exotic second doublet, leading eventually to same-sign dilepton signals. We perform a signal-to-background analysis at the 14 TeV LHC and show that discovery seems possible with LHC Run 2 data already at hand.

hep-ph↗

arXiv2024

Accommodating the LHC Charged Higgs Boson Excess at 130 GeV in the General Two-Higgs Doublet Model

Charged Higgs bosons are common predictions in most extensions of the Standard Model (SM) Higgs sector. Therefore, their observation would elucidate the nature of the Higgs sector. Motivated by the ATLAS collaboration's latest analysis performed with $139~\text{fb}^{-1}$ of Run 2 data intended to search for charged Higgs boson, produced in top quark decay and subsequently decaying via $H^\pm \rightarrow cb$, where an excess with a local significance of $3σ$ is observed at $m_{H^\pm} = 130~\rm{GeV}$, we discuss here the possibility of explaining such excess in the context of the general 2-Higgs Doublet Model (2HDM type-III), after satisfying all theoretical and up-to-date experimental constraints. We also propose phenomenological scenarios to further explore the mass region around 130 GeV in the four Yukawa types of the 2HDM type-III and suggest alternative decay channel $H^\pm \rightarrow cs$ and/or $H^\pm \rightarrow W^{\pm *}h$ to probe the nature of the observed excess (if it is not a statistical fluctuation). Future searches for $H^\pm$ will be critical in confirming or refuting the first hint of a light charged Higgs boson at the LHC.

hep-ph↗

arXiv2024

Reconstructing the general 2HDM charged Higgs boson at the LHC

We study the discovery prospects for a charged Higgs boson via the $b g\to c H^- \to c \bar t b$ process at the Large Hadron Collider (LHC). Focusing on the general Two Higgs Doublet Model (G2HDM) that possesses extra Yukawa couplings, the process is controlled by extra top couplings $ρ_{tc}$ and $ρ_{tt}$, which can drive electroweak baryogenesis (EWBG) to account for the baryon asymmetry of the Universe (BAU). We propose benchmark points (BPs) and demonstrate that evidence could emerge at 14 TeV LHC and luminosity of 300 fb$^{-1}$, with discovery potential at 600 fb$^{-1}$.

hep-ph↗

arXiv2022

Charged Higgs boson production via $pp \rightarrow H^\pm bj$ at the LHC

The searches for charged Higgs bosons can be used to probe new physics at the LHC. In the current study, we concentrate on the associated production of the charged Higgs boson with the bottom quark and the jet in Two-Higgs Doublet Model (2HDM) type-I as promising mode for a light $H^\pm$, i.e. $m_{H^\pm}<m_t$. For this we consider the two situations where $h$ or $H$ is the SM-type Higgs boson discovered with a mass close to 125 GeV and investigate its bosonic decays, namely $H^{\pm} \to W^{\pm} h$ and/or $H^{\pm} \to W^{\pm} A$. The potential signals at the LHC are then discussed, under both theoretical and experimental constraints. Over a substantial region of the 2HDM type-I parameter space, a promising alternative signals that could be used for the discovery of $H^{\pm}$ states at the LHC are identified as $qbW+2b/2τ/2γ$.

hep-ph↗

arXiv2021

New Light $H^\pm$ Discovery Channels at the LHC

A light charged Higgs boson has been searched for at the Large Hadron Collider (LHC) via top (anti)quark decay, i.e., $t \to b H^+$, if kinematically allowed. In this contribution, we propose new channels for light charged Higgs boson searches via the pair productions $pp\to H^\pm h/A$ and $pp\to H^+ H^-$ at the LHC in the context of the Two-Higgs Doublet Model (2HDM) Type-I. By focusing on a case where the heavy H state is the Standard Model (SM)-like one already observed, we investigate the production of the aforementioned charged Higgs bosons and their bosonic decay channels, namely, $H^\pm \to W^\pm h$ and/or $H^\pm \to W^\pm A$. We demonstrate that such production and decay channels can yield substantial alternative discovery channels for $H^\pm$ bosons at the LHC. Finally, we propose eight benchmark points (BPs) to motivate the search for such signatures.

hep-ph↗