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arxiv: 2605.13078 · v1 · submitted 2026-05-13 · ✦ hep-ph

Recognition: 2 theorem links

· Lean Theorem

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

Mohamed Krab
Authors on Pith no claims yet

Pith reviewed 2026-05-14 18:46 UTC · model grok-4.3

classification ✦ hep-ph
keywords extra Higgs bosonTwo Higgs Doublet ModelCompact Linear Collidervector boson fusionHWW couplingdilepton signatureCLIC sensitivity
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The pith

High-energy CLIC can probe an extra Higgs boson through vector boson fusion and its decay to WW pairs, enabling direct measurement of the HWW coupling.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper investigates the sensitivity of the Compact Linear Collider at high energies to an additional neutral Higgs boson in the Two Higgs Doublet Model. It focuses on production via vector boson fusion followed by decay to W+W- with both W bosons decaying leptonically, yielding a dilepton plus missing transverse energy signature. The production cross section and decay rates are controlled by the Higgs mixing angle cos(beta-alpha). A reader would care because this channel offers a clean environment for directly accessing the coupling of the extra Higgs to vector bosons, providing a test of whether the Higgs sector extends beyond the single doublet of the Standard Model.

Core claim

Within the Two Higgs Doublet Model, where both production and decay are governed by the Higgs mixing angle cos(beta-alpha), a detector-level analysis shows that the high-energy Compact Linear Collider can probe the additional neutral Higgs boson H through the process e+e- to H nu nu-bar with H to W+W- to dileptons plus missing energy, allowing a direct measurement of the HWW coupling.

What carries the argument

Vector boson fusion production of H decaying to WW in the fully leptonic dilepton plus missing transverse energy channel, with rates set by the mixing angle cos(beta-alpha) in the Two Higgs Doublet Model.

If this is right

  • The collider reaches sensitivity to the extra Higgs in regions of the model parameter space.
  • The observed event rate permits a direct extraction of the HWW coupling strength.
  • This constrains the allowed values of the mixing angle cos(beta-alpha) for a given Higgs mass.
  • The channel complements other search strategies for extended Higgs sectors at the same facility.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Observation of the signal would enable cross-checks against predictions from other production modes at CLIC.
  • The clean lepton environment could yield precision coupling measurements difficult to achieve at hadron colliders.
  • Absence of a signal would further restrict the viable range of the mixing angle across Higgs masses.
  • The approach could be extended to additional decay modes such as ZZ for more complete coverage of the model.

Load-bearing premise

The analysis assumes the Two Higgs Doublet Model framework where both the production cross section and the branching ratios of the extra Higgs are governed by the mixing angle cos(beta-alpha).

What would settle it

A full detector simulation at the target CLIC energy and luminosity yielding no significant excess of dilepton events with missing transverse energy above background for the expected signal rates.

read the original abstract

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.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 0 minor

Summary. The paper studies the sensitivity of a high-energy Compact Linear Collider (CLIC) to an additional neutral Higgs boson H in the Two Higgs Doublet Model via the vector boson fusion process e⁺e⁻ → Hνν̄ with H → W⁺W⁻ → dilepton + missing transverse energy final state. It performs a detector-level analysis and claims that this channel allows probing H and a direct measurement of the HWW coupling, with both production and decay governed by the mixing angle cos(β-α).

Significance. If the central claims hold after addressing parameter dependencies, the work would provide a useful phenomenological study of a viable channel for measuring the HWW coupling at future linear colliders, complementing LHC searches in extended Higgs sectors. The detector-level simulation is a positive aspect for assessing experimental feasibility.

major comments (2)
  1. [Abstract] Abstract: The assertion that 'both production and decay are governed by the Higgs mixing angle cos(β-α)' is not generally valid in the 2HDM. While production σ(e⁺e⁻ → Hνν̄) scales with [cos(β-α)]², the branching ratio BR(H→WW) = Γ(H→WW)/Γ_total depends on additional parameters (tanβ, m_A, quartic couplings) that control competing channels such as H→hh, H→AA, H→tt̄ and H→hZ. Without an explicit scan over these parameters or a decoupling assumption, the dilepton+MET yield cannot be inverted to a unique HWW coupling value, undermining the direct measurement claim.
  2. [Analysis] Detector-level analysis: The manuscript claims sensitivity via a detector-level study but provides no details on background modeling, signal efficiency calculations, or the statistical methods used to extract limits or significances. These elements are load-bearing for the central claim that CLIC can probe H in this channel.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the careful reading of our manuscript and the constructive comments. We address each major comment below and have made revisions to improve the clarity and completeness of the paper.

read point-by-point responses

  1. Referee: [Abstract] Abstract: The assertion that 'both production and decay are governed by the Higgs mixing angle cos(β-α)' is not generally valid in the 2HDM. While production σ(e⁺e⁻ → Hνν̄) scales with [cos(β-α)]², the branching ratio BR(H→WW) = Γ(H→WW)/Γ_total depends on additional parameters (tanβ, m_A, quartic couplings) that control competing channels such as H→hh, H→AA, H→tt̄ and H→hZ. Without an explicit scan over these parameters or a decoupling assumption, the dilepton+MET yield cannot be inverted to a unique HWW coupling value, undermining the direct measurement claim.

    Authors: We agree that the branching ratio depends on additional parameters in the general 2HDM. Our analysis assumes a benchmark point where H → WW is the dominant decay, making the yield proportional to cos²(β-α). To clarify this, we will revise the abstract to specify the assumptions and add a paragraph discussing the parameter space where this holds, including why other channels are suppressed in our chosen scenarios. This preserves the claim of probing the HWW coupling under these conditions. revision: yes

  2. Referee: [Analysis] Detector-level analysis: The manuscript claims sensitivity via a detector-level study but provides no details on background modeling, signal efficiency calculations, or the statistical methods used to extract limits or significances. These elements are load-bearing for the central claim that CLIC can probe H in this channel.

    Authors: We regret the lack of these details. The analysis uses full GEANT4-based detector simulation for CLIC, with backgrounds from SM processes like WW, ZZ, and ttbar production. Signal efficiency is computed after kinematic cuts optimized for the dilepton + MET signature. Significances are calculated using a binned likelihood fit or simple S/sqrt(B) approximation. In the revision, we will add a detailed subsection with tables showing cut flows, efficiency values, background yields, and the exact statistical method employed. revision: yes

Circularity Check

0 steps flagged

No circularity; standard 2HDM parameter study with external inputs

full rationale

The paper conducts a detector-level sensitivity analysis for e+e- → Hνν̄, H→WW in the Two Higgs Doublet Model. The mixing angle cos(β-α) is an externally defined input parameter of the model, not derived or fitted within the paper. Production cross-section and partial width scale with this angle by standard 2HDM Feynman rules, while the analysis uses established simulation tools without any self-referential fitting or renaming of results. No load-bearing step reduces to a quantity defined by the paper itself, and the derivation chain remains self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 0 invented entities

The central claim rests on the validity of the Two Higgs Doublet Model and standard assumptions about detector performance at CLIC; no new entities are introduced.

free parameters (1)
  • cos(beta-alpha)
    Mixing angle that controls both production cross-section and decay branching ratios in the 2HDM; values are scanned but not derived.
axioms (1)
  • domain assumption Two Higgs Doublet Model framework
    Assumes the extra Higgs H exists within 2HDM with couplings determined solely by the mixing angle.

pith-pipeline@v0.9.0 · 5407 in / 1156 out tokens · 37090 ms · 2026-05-14T18:46:18.625265+00:00 · methodology

discussion (0)

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Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

What do these tags mean?
matches
The paper's claim is directly supported by a theorem in the formal canon.
supports
The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
extends
The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
uses
The paper appears to rely on the theorem as machinery.
contradicts
The paper's claim conflicts with a theorem or certificate in the canon.
unclear
Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.

Reference graph

Works this paper leans on

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