arXiv subjects

Quang Hoang-Minh Pham

Publications and source records attributed to Quang Hoang-Minh Pham.

6 recordsLinked to original sources

arXiv2026

Probing dark matter through charged Higgs pair production at future multi-TeV muon colliders: A machine-learning analysis

Probing dark matter (DM) via charged Higgs pair production at future multi-TeV muon colliders is investigated within the Inert Doublet Model (IDM). The viable parameter space of the IDM is first updated by incorporating theoretical constraints and current experimental data. Based on the allowed parameter space, we evaluate DM relic density and compare the results with the latest constraints from direct DM detection experiments. The resulting parameter points consistent with all DM constraints are subsequently employed to study charged Higgs pair production at future multi-TeV muon colliders, including the subsequent decays of the charged Higgs bosons into Standard Model (SM) particles in association with DM candidate. In particular, we study the following production processes: $μ^- μ^+ \to ν_μ \barν_μ H^{\pm} H^{\mp} \to \ell^+ \ell^- + ν_μ \barν_μ ν_{\ell} \barν_{\ell} HH$, $μ^- μ^+ \to ν_μ \barν_μ H^{\pm} H^{\mp} \to \ell^\pm + 2\,\text{jets} + ν_μ \barν_μ ν_{\ell} HH$ and $μ^- μ^+ \to ν_μ \barν_μ H^{\pm} H^{\mp} \to 4\,\text{jets} + ν_μ \barν_μ HH$ for $\ell =e, μ$. The signal significance is evaluated against the corresponding SM backgrounds using both cut-based and machine-learning (ML) approaches. We find that ML framework substantially enhances the sensitivity to the signal processes compared with the conventional cut-based analysis. Furthermore, our results indicate that the DM signals through charged Higgs pair production can be indirectly probed with a statistical significance exceeding $5σ$ for several viable benchmark points at future multi-TeV muon colliders.

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arXiv2026

Neutral scalar pair productions through $W$-boson fusion at multi--TeV muon colliders

Full one-loop electroweak radiative corrections to $μ^- μ^+ \to W^\pm W^\mp \to hh$ in the Standard Model are computed for the first time in this work. We then evaluate neutral scalar pair production through vector boson fusion at multi--TeV muon colliders within Two-Higgs-Doublet Model (THDM). In the phenomenological analysis, the enhancement factor, defined as the ratio of the cross sections for SM-like Higgs pair production in the THDM with respect to the corresponding ones in the SM, is examined over the viable regions of the parameter space in the Type-X and Type-Y THDMs. Our findings show that this ratio can reach a factor of $3$ in several regions within the valid parameter space of the Type-X THDM, whereas it ranges from $0.91$ to $0.96$ over the entire parameter space of the Type-Y THDM. Finally, we scan the cross sections for double CP-odd Higgs production over the updated parameter space of the Type-X and Type-Y THDMs. In the Type-Y case at $\sqrt{s} = 10$~TeV with an integrated luminosity of $\mathcal{L} = 10000~\text{fb}^{-1}$, CP-odd Higgs pair production in the $t\bar{t}b\bar{b}$ final state, with subsequent top-quark decays into leptons and bottom quarks taken into account, can be tested with a statistical significance exceeding the $2σ$ level at several viable parameter points.

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arXiv2025

Production of charged Higgs bosons associated with CP-even Higgs bosons at future multi--TeV muon colliders

We report the first results for charged Higgs boson production associated with CP-even Higgses at future multi--TeV muon colliders within the scenario of the Type-Y Two-Higgs-Doublet Model (THDM). The valid parameter regions in the Type-Y THDM are first updated, and based on the allowed parameter space, all two-body decay channels of the charged Higgs boson are then computed with the help of {\tt H-COUP}. Both production processes $μ^- μ^+ \to H^\pm H^\mp h, H^\pm H^\mp H \to t\bar{t} b\bar{b} h, t\bar{t} b\bar{b}H$ are scanned over the constrained parameter space of the considered model. The production cross sections can reach $\sim 0.5$ fb in several regions of the parameter space. The results provide an opportunity to probe charged Higgs bosons produced in association with the heavy CP-even Higgses at the high integrated luminosities proposed for future multi--TeV muon colliders. Furthermore, we evaluate the signal significances for $μ^- μ^+ \to H^\pm H^\mp h \to t\bar{t} b\bar{b} h \to t\bar{t} b\bar{b} b\bar{b}$ with respect to the Standard Model backgrounds. We also estimate the significances by including the top quark decay into leptons and bottom quarks and considering $b$-tagging. Thanks to the high integrated luminosities anticipated at future multi--TeV muon colliders,we find that the signal significances can exceed $\sim 3σ$ at several benchmark points selected in the viable parameter space of the Type-Y THDM.

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arXiv2025

Charged Higgs bosons associated with neutral gauge bosons at future multi--TeV muon colliders

The first results for charged Higgs pair production associated with neutral gauge bosons at future multi--TeV muon colliders are presented within the framework of the Two-Higgs-Doublet Model. In the phenomenological studies for the production processes, we first update the parameter space of the Type-X Two-Higgs-Doublet Model. From the viable regions of the parameter space, we compute the production cross sections, including all two-body decay modes of the charged Higgs boson. We mention that all two-body decay modes of the charged Higgs boson are evaluated with one-loop electroweak corrections, with two-loop QCD corrections also included for the decays of the charged Higgs into two fermions. The signal significances are also examined for several benchmark points within the updated parameter space. It is worth emphasizing that the production cross sections used for computing the significances in this work include initial-state radiation corrections up to two-loop order. With the help of the high integrated luminosity planned for future multi--TeV muon colliders, the production signals can be observed with a statistical significance exceeding $5σ$ for several selected points within the allowed parameter space.

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arXiv2025

One-loop expressions for $H^{\pm} \rightarrow W^{\pm} Z$ and their implications at muon--TeV colliders

One-loop contributions for decay process $H^{\pm} \rightarrow W^{\pm}Z$ within the Two-Higgs-Doublet Model are computed in the general $\mathcal{R}_ξ$ gauge, and its phenomenological applications at future muon--TeV colliders are studied in this paper. The analytic results are confirmed by several consistency tests, for example, the $ξ$-independence, the renormalization-scale stability and the ultraviolet finiteness of the one-loop amplitude. We first perform an updated parameter scan of the Type-X THDM in the phenomenological studies. The production of charged Higgs boson pairs at future muon--TeV colliders is investigated through the two processes $μ^+μ^- \rightarrow H^+H^- \rightarrow W^{\pm}W^{\mp}Zh$ and $μ^+μ^- \rightarrow γγ\rightarrow H^+H^- \rightarrow W^{\pm}W^{\mp}Zh$. Both signal events and their significances are evaluated with taking into account the corresponding Standard Model backgrounds. We find that the signal significances can exceed $5σ$ at several benchmark points in the viable parameter space of the Type-X THDM.

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arXiv2025

Probing one-loop--induced decay channel $H^\pm \to W^\pmγ$ in the Two Higgs Doublet Models at muon-TeV colliders

In this work, we study the one-loop--induced decay channel $H^{\pm} \rightarrow W^{\pm}γ$ in the general $\mathcal{R}_ξ$ gauge within Two Higgs Doublet Models. We analytically verify the gauge invariance ($ξ$-independence), ultraviolet finiteness, and renormalization-scale independence of the one-loop form factors, thereby confirming the consistency of our calculations. On the phenomenological side, we perform a parameter scan of the Type-I THDM and, based on the viable parameter space, evaluate the branching ratios of this decay process. Furthermore, we investigate charged Higgs pair production at muon-TeV colliders through the representative processes $μ^+μ^- \rightarrow H^{+}H^{-} \rightarrow W^+W^- hγ$ and $μ^+μ^- \rightarrow γγ\rightarrow H^{+}H^{-} \rightarrow W^+W^- hγ$, as typical applications of our results. The events for the processes are computed within the allowed parameter regions of the Type-I THDM. The corresponding signal significances are evaluated, including the relevant Standard Model backgrounds, at a center-of-mass energy of $\sqrt{s} = 3$~TeV. With the high integrated luminosity expected at muon-TeV colliders, reaching up to $\mathcal{L} = 3000~\text{fb}^{-1}$, our analysis indicates that the signals can be detected with a statistical significance of $5σ$ for several benchmark scenarios in the viable parameter space of the Type-I THDM.

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