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REVIEW 4 major objections 4 minor 69 references

Two singlet-extended two-Higgs-doublet models that both fit the 95 GeV excesses can be told apart at 2σ by combining four-top production at the HL-LHC with di-Higgs measurements at ILC500.

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

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2026-08-01 01:48 UTC pith:32XITCRR

load-bearing objection Useful and credible follow-up, but the HL-LHC four-top analysis silently omits the singlet-like pseudoscalar from the final state, so those α4 limits are not yet reliable; the di-Higgs part stands. the 4 major comments →

arxiv 2607.25670 v1 pith:32XITCRR submitted 2026-07-28 hep-ph

The 95 GeV Excess in Models with Two Higgs Doublets plus One Singlet: Model Distinction via Four-top Final States and Triple Higgs Couplings

S. Heinemeyer , C. Li , G. Moortgat-Pick , D. Schieber This is my paper
classification hep-ph PACS 12.60.Fr14.80.Bn13.85.Ni
keywords N2HDM2HDMS95 GeV excessfour-top productiontrilinear Higgs couplingsdi-Higgs productionHL-LHCα4 limit
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

The paper aims to show that two popular extensions of the Higgs sector, the two-Higgs-doublet model with a real singlet (N2HDM) and the one with a complex singlet (2HDMS), remain distinguishable at future colliders even when they are tuned to reproduce the same 95 GeV excesses and the same 125 GeV Higgs properties. It introduces a quantitative criterion, the 'α4 limit,' defined as the smallest deviation from the N2HDM-limit mixing angle (α4 = π/2) at which the two models' cross-section predictions differ by at least 2σ. The discrimination is achieved through four-top final states at the HL-LHC, which probe the different CP-odd sectors, and through di-Higgs production at ILC500, which probes the trilinear Higgs couplings that differ because of the extra cubic terms in the 2HDMS potential. The authors show that the discriminatory power grows with the mass splitting between the two pseudoscalars of the 2HDMS and with a smaller singlet VEV. If correct, this gives a general strategy for separating extended Higgs sectors that appear identical in all current data.

Core claim

The central discovery is that the type II N2HDM and 2HDMS, in benchmark scenarios reproducing the 95 GeV γγ and bb excesses, can be distinguished at 2σ by combining four-top production at the HL-LHC and di-Higgs production at ILC500. The quantitative handle is the α4 limit: the smallest value of |π/2 − α4| for which the 2HDMS cross-section prediction differs from the N2HDM by at least 2σ. The limits approach the N2HDM limit for large pseudoscalar mass splittings and small vS, and the paper provides analytical expressions for the trilinear Higgs couplings that trace the difference to the additional cubic interactions µ12 and µS1 present in the 2HDMS potential.

What carries the argument

The central object is the 'α4 limit' defined in Eq. (72): the smallest value of |π/2 − α4| at which the 2HDMS and N2HDM cross-section predictions differ by at least 2σ, where α4 is the mixing angle between the doublet and singlet components of the two CP-odd states in the 2HDMS. The analytical engine is the derived set of trilinear Higgs couplings (Eqs. 44–45), which isolates the 2HDMS-specific contributions ∝ (m_a2^2 − m_a1^2)/(vS sin α4 cos α4) and shows how they vanish in the N2HDM limit yet grow with pseudoscalar mass splitting and with inverse vS.

Load-bearing premise

The four-top analysis assumes that only the heavy CP-even h3 and the doublet-like pseudoscalar aD contribute to the four-top final state, omitting the singlet-like pseudoscalar aS which for maS > 2mt (e.g., 500 GeV) can also produce four-top via ttaS → tttt; if this contribution is non-negligible, the quoted HL-LHC α4 limits are mis-estimated.

What would settle it

Compute the full pp → tttt cross-section in the 2HDMS at maS = 500 GeV including pp → ttaS with aS → tt, using the same benchmark parameters and cuts as the HL-LHC study; if the resulting α4 limit moves by more than the quoted 2σ band, the current four-top analysis is incomplete. Alternatively, a dedicated search for four-top events with invariant mass near maS at the HL-LHC would directly test the aS contribution.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • Combining the four-top rate at the HL-LHC with the three di-Higgs channels at ILC500 yields 2σ α4 limits that, for pseudoscalar mass splittings of 100–200 GeV, cover most of the currently allowed benchmark plane (tan β ≲ 3, mA ∈ [600, 700] GeV).
  • The discrimination power improves with the mass splitting ∆ma between the doublet- and singlet-like pseudoscalars: larger ∆ma gives α4 limits closer to π/2, and for ∆ma = 200 GeV the 2HDMS is distinguished in the entire allowed region except small slivers.
  • At ILC500 the Zh95h95 channel provides the strongest individual constraint; the combination with Zh95h125 and Zh125h125 extends distinguishability to regions (e.g., large tan β) where four-top is less sensitive.
  • The α4 limits degrade with increasing vS: for ∆ma = 25 GeV no 2σ limit survives beyond vS ≈ 150 GeV, while for ∆ma = 125 GeV limits persist up to vS ≈ 400 GeV.

Where Pith is reading between the lines

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

  • The omission of the aS-mediated ttaS → tttt process in the four-top channel is testable: repeating the analysis with maS = 500 GeV and including this diagram is expected to shift the α4 limits on the α4 > π/2 side, where the aS coupling is largest.
  • The α4-limit definition could be exported to other BSM scenarios; e.g., in a CP-violating 2HDMS the same observables would constrain a phase rather than an angle, and the four-top channel would become sensitive to CP-violating interference.
  • The dependence on vS suggests a complementary probe: precision measurements of the Higgs self-coupling at the HL-LHC (via gg → hh) might already provide weaker but model-independent limits on the 2HDMS parameter space before ILC runs.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

4 major / 4 minor

Summary. The paper studies two singlet-extended two-Higgs-doublet models, the N2HDM and the 2HDMS, in type-II Yukawa realizations, using a benchmark that reproduces the 95 GeV γγ and bb excesses while keeping h2 as the 125 GeV SM-like Higgs. It derives compact analytic expressions for the trilinear Higgs couplings, introduces the "α4 limit" as the smallest deviation from the N2HDM limit that yields a 2σ distinction, and evaluates these limits in two complementary channels: four-top production at the HL-LHC and di-Higgs production at ILC500. The central quantitative outputs are the projected α4 limits in the mA–tanβ planes shown in Figs. 8–10 and Figs. 17–20.

Significance. If the projections hold, the paper offers a useful and fairly general strategy for distinguishing extended Higgs sectors that have identical CP-even phenomenology but different CP-odd sectors. The analytic THC expressions in Sec. 2.6 and the α4-limit concept are valuable beyond the specific 95 GeV benchmark. The numerical pipeline is based on public tools (SARAH/SPheno/MadGraph/HiggsTools) and the constraints are handled in a standard way. However, the quantitative α4 limits are conditional on several idealizations: an approximate rescaling of HL-LHC efficiencies, an optimistic ILD uncertainty model, and omission of the singlet-like pseudoscalar contribution to the four-top final state. These do not destroy the qualitative framework, but they do affect the central numerical claim.

major comments (4)
  1. [Sec. 3.1, Eq. (73)] The four-top BSM rate in Eq. (73) is written as the incoherent sum of pp→tt̄aD and pp→tt̄h3 only. Yet Eq. (75) gives c_{aS tt} ∝ cos α4/tanβ, and for the maS = 500 GeV scenarios used in Fig. 7 and Fig. 10, aS→tt is kinematically open. At the quoted α4 limits (|π/2 − α4| ≈ 0.25–0.30 rad), cos²α4 ≈ 0.06–0.09, which is non-negligible relative to sin²α4 ≈ 0.91–0.94; the tt̄aS production cross-section at 500 GeV is also larger than at 600 GeV. The aS term grows as α4 moves away from π/2, flattening the total four-top rate and shifting the α4 limits. No estimate of σ(pp→tt̄aS)BR(aS→tt) is given. At minimum the authors must quantify this contribution or justify its omission before the HL-LHC discrimination claim can be accepted.
  2. [Sec. 3.2, Eqs. (77)–(80)] The HL-LHC projections rescale efficiencies ϵs and ϵb from Ref. [51], which considered degenerate H/A states, to the benchmark with m_aD = 600 GeV and m_h3 = 650 GeV. The paper states that the analysis remains valid for |m_h3 − m_aD| ≤ 50 GeV, but no validation is provided. Efficiencies for a CP-even and a CP-odd scalar of different masses can differ in tt̄ϕ production and in the four-top selection. This enters directly into Δσs in Eq. (80) and therefore into all α4 limits in Figs. 8–10. A dedicated efficiency study, or at least a sensitivity scan over ϵs and ϵb, is needed.
  3. [App. B, Eqs. (136)–(137)] The di-Higgs uncertainty estimate relies on a constant 0.674 rescaling of the ILD uncertainty and on the assumption that all backgrounds bi remain unchanged in the BSM scenarios. Since the α4 limits in Sec. 4.3 are obtained from Eq. (99) with Δσ from Eq. (137), an optimistic uncertainty rescaling directly strengthens the quoted limits. The paper acknowledges this, but it would be useful to show how the limits change if the 0.674 factor is removed or if the background rates are varied within a plausible range; otherwise the ILC discrimination claim is conditional on a single ad hoc uncertainty model.
  4. [Sec. 2.9, Eq. (72)] The α4-limit definition assumes all free parameters are known perfectly and are identical between the two models, except for α4. This is acknowledged for the ILC part in Sec. 4.3, but the same assumption also underlies the HL-LHC α4 limits in Figs. 8–10. The 95 GeV excess constraints and future Higgs measurements will determine these parameters with finite uncertainties, which will degrade the 2σ distinction power. The abstract and conclusions should state more prominently that the quoted limits are idealized, not including parametric uncertainties.
minor comments (4)
  1. [Sec. 4.3] The text says "di-Higgs production at the ILC1000" in the opening sentence of Sec. 4.3, but the actual cross-sections and uncertainty estimates in this section are for ILC500 (√s = 500 GeV, L = 4 ab⁻¹). Please correct the inconsistency.
  2. [Throughout] There are multiple typos and minor wording issues, e.g., "containts", "asymmetricly", "we we", "distrinction", "scenarious", and "an good description". A careful proofread is needed.
  3. [Sec. 2.8.3] The phrase "the unbalanced uncertainty of CMS measurement" should be "asymmetric uncertainty". Also, it would help to state explicitly that the threshold χ²95 ≤ 3.523 corresponds to the 1σ region for three observables.
  4. [Sec. 4.2, Fig. 15] The text around Eq. (97)–(98) explains the near-cancellation in the N2HDM Zh1h1 rate. The notation ch1V V λh1h1h1 is clear, but a diagram or a one-line amplitude expansion would make the cancellation more transparent for the reader.

Circularity Check

0 steps flagged

No significant circularity: benchmark inputs are fitted, but the four-top and di-Higgs distinction observables are computed independently.

full rationale

The paper's central derivation is not circular. The benchmark parameters (ch1VV≈0.35, ch1bb/ch1tt≈0.8, ε=0.05, vS=120 GeV, Tab. 2) are fitted to the 95 GeV excesses, but they enter as inputs; the paper does not claim to predict those excesses. The quantitative results—four-top cross-sections, di-Higgs cross-sections, and the α4 limits defined in Eq. (72)—are computed from the Lagrangian via the THC expressions (44)-(45) and the coupling dependences (73)-(75), and they are not used to define the benchmark inputs. The α4 limit is a new projection measure, not a renamed fit. Constraints use public/external tools (HiggsTools, SPheno, EVADE, MadGraph) and experimental data; the self-citations [19], [22], [49] provide technical derivations or prior scans, but the central model-distinction claim does not reduce to those citations. No uniqueness theorem is invoked. One internal inconsistency is flagged per the review rule: Eq. (73) defines the BSM four-top rate as the incoherent sum of ttaD and tth3 only, while Eq. (75) gives the singlet-like pseudoscalar aS a non-zero top-quark coupling ∝ cosα4/tanβ; for maS=500 GeV, pp→ttaS→tttt is kinematically open and is omitted. This is a modeling/correctness issue, not a circular reduction: the α4 limit is not equivalent to an input by construction. Therefore no circular step is present; the score of 2 reflects only minor non-load-bearing self-citations in the constraint and tooling sections.

Axiom & Free-Parameter Ledger

8 free parameters · 9 axioms · 0 invented entities

No new particles or forces are introduced; both models and the 95 GeV excess predate this paper. The central claim depends instead on a set of benchmark parameters fitted to the excesses, on standard theoretical constraints, and on several optimistic collider-uncertainty assumptions. The most fragile input is the four-top channel's neglect of the singlet-like pseudoscalar contribution, combined with the explicit neglect of parametric uncertainties in the e+e− projections.

free parameters (8)
  • tan β = 1.5 (scanned in [1,3] and [2.5,3])
    Benchmark choice; controls Yukawa couplings and four-top cross-sections.
  • c_{h1 VV} = 0.35
    Effective coupling input chosen to reproduce the LEP bbbar excess at 95 GeV.
  • c_{h1 bb}/c_{h1 tt} = 0.8
    Chosen to reproduce the diphoton excesses via the inverse scaling of mu_gamma_gamma.
  • ε = 0.05
    Offset from the alignment limit, chosen to retain BSM properties while satisfying HiggsSignals constraints.
  • v_S = 120 GeV
    Singlet VEV; chosen small because THC differences grow as 1/v_S.
  • m_h3, m_H±, m_A, μhat = 650, 650, 600, 600 GeV (benchmark)
    Heavy sector masses chosen to satisfy BSM search and flavor constraints while keeping |m_h3 - m_aD| ≤ 50 GeV for the four-top efficiency rescaling.
  • m_aS / Δma = varied (25-500 GeV depending on plane)
    Singlet-like pseudoscalar mass and mass splitting with doublet-like pseudoscalar; central driver of THC differences.
  • α4 = scanned in [π/4, 3π/4]
    CP-odd mixing angle of the 2HDMS; the output 'α4 limit' is defined in terms of scanning this parameter.
axioms (9)
  • standard math Perturbative unitarity, boundedness-from-below, and vacuum stability constraints from Refs. [1,22,23-25] are correct and sufficient.
    Used in Sec. 2.8.1 to define allowed parameter points; not re-derived in this paper.
  • domain assumption Z2/Z3 symmetry structure and type II Yukawa realization correctly define the N2HDM and 2HDMS scalar sectors.
    Sec. 2.1; the entire comparison is performed in this model class.
  • ad hoc to paper The benchmark scenario must describe the 95 GeV γγ and bb excesses within 1σ while h2 is the 125 GeV SM-like Higgs.
    Sec. 2.8.3 and Tab. 2; this embedding is motivated by experiment but is a choice, not a consequence of the models.
  • domain assumption Narrow-width approximation is valid for computing 95 GeV signal strengths and four-top contributions from heavy Higgses.
    Eqs. (63)-(64) and Sec. 3.1; used throughout to convert cross-section times branching ratio into rates.
  • ad hoc to paper HL-LHC four-top efficiencies from Ref. [51], derived for degenerate H/A masses, remain valid for |m_h3 - m_aD| ≤ 50 GeV.
    Sec. 3.2; the paper explicitly assumes this mass-window validity without a detector-level check.
  • ad hoc to paper ILD di-Higgs uncertainties can be rescaled by a constant 0.674 factor, with background rates unchanged in the BSM scenarios.
    App. B, Eq. (137); the paper calls this an approximation and notes background changes are neglected.
  • ad hoc to paper All model parameters are known perfectly when computing α4 limits (no parametric uncertainties).
    Sec. 4.3 explicitly states this is an optimistic case and that including parametric uncertainties would degrade the limits.
  • domain assumption Only h3 and the doublet-like aD contribute to the four-top final state; the singlet-like aS contribution is neglected.
    Eq. (73) sums only aD and h3, but Eq. (75) gives aS a non-zero top coupling; no justification is given for dropping aS when maS > 2mt.
  • domain assumption The propagator approximation D95 ≈ D125 is used to show cancellation of one class of Δλ terms in di-Higgs strahlung.
    Eqs. (53)-(54); the paper notes the approximation is not exact in the numerical benchmark with mh1 = 95.4 GeV, mh2 = 125.09 GeV.

pith-pipeline@v1.3.0-alltime-deepseek · 34416 in / 17124 out tokens · 178198 ms · 2026-08-01T01:48:58.621445+00:00 · methodology

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read the original abstract

We investigate the prospects for experimentally distinguishing the Next-to-Two-Higgs-Doublet Model (N2HDM) and the Two-Higgs-Doublet Model with a Complex Singlet (2HDMS) in the Yukawa type II realization. Both models can successfully accommodate the reported Higgs-boson excesses around 95 GeV while satisfying current theoretical and experimental constraints, leading to very similar predictions for the observed Higgs spectrum and signal strengths. We analyze how they can nevertheless be discriminated through observables sensitive to the scalar potential and the CP-odd sector. Analytical expressions for the trilinear Higgs couplings are derived, exhibiting characteristic contributions induced by the additional cubic interactions of the 2HDMS. We study the corresponding phenomenology in two complementary collider environments: four-top production at the High-Luminosity LHC, probing the different pseudoscalar sectors. In a second step we analyze Higgs pair production at a future high-energy $e^+e^-$ collider, providing direct sensitivity to the trilinear Higgs couplings. We quantify the potential to distinguish the two models by introducing the minimum deviation from the N2HDM limit required for a $2\sigma$ difference between the two models. Although our numerical analysis focuses on benchmark scenarios describing the 95 GeV excesses, the proposed approach provides a general framework for discriminating between singlet-extended Higgs sectors at future colliders.

Figures

Figures reproduced from arXiv: 2607.25670 by C. Li, D. Schieber, G. Moortgat-Pick, S. Heinemeyer.

Figure 1
Figure 1. Figure 1: General trilinear Higgs self-coupling vertex ∝ λ model hihjhk . expanding the Higgs potential of the N2HDM (see eq. Eq. (13)) or 2HDMS (see Eq. (14)) using the field rotations in Eq. (26) and collecting all terms ∝ hihjhk, λ model hihjhk = ∂ 3V model ∂hi∂hj∂hk [PITH_FULL_IMAGE:figures/full_fig_p009_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: N2HDM benchmark plane 1 (left) and 2 (right). The green regions indicate the parameter space allowed by the theoretical and experimental constraints. For the other color coding: see legend. The colors show all possible exclusions from the imposed constraints however only unitarity, boundedness from below and Higgs bounds excluded parameter points in this scan. 16 [PITH_FULL_IMAGE:figures/full_fig_p017_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Constraints of the extended region to the 2HDMS for the benchmark scenario. The mass of the doublet like CP-odd Higgs is shown in red. The greyed out regions violate the mass hierarchy of the CP-odd Higgs bosons. satisfy all the experimental and theoretical constraints. As an example, we show in [PITH_FULL_IMAGE:figures/full_fig_p018_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Schematic plot of possible scenarious encountered during computation of the α4 limits. 3 HL-LHC Prospects for Model Distinction 3.1 Four-top final state at the hadron collider At the (HL-)LHC the heavy BSM Higgs-bosons, h3 and A, can be produced in association with top quarks. This includes the channels of ttϕ, tW ϕ and tqϕ, with ϕ denoting collectively the heavy neutral Higgs bosons, with the mass mϕ. Her… view at source ↗
Figure 5
Figure 5. Figure 5: Example diagram for the ttH associated production process. For mϕ ≥ 2mt the BSM Higgs can (potentially dominantly) decay to a tt¯ final state, which then contributes to the four-top final state at the (HL-)LHC. Within the 2HDMS and N2HDM, the BSM contribution to the four-top signal rate would be a combination of the CP-even state h3 and the CP-odd state doublet dominated aD, which add incoherently. In part… view at source ↗
Figure 6
Figure 6. Figure 6: The BRs of aD as a function of maS , with α4 = 3 4 π, and the other parameters are chosen as for the benchmark scenario in Tab. 2. can be considered to be experimentally distinguishable from the N2HDM, where the “α4 limit” (see Sec. 2.9) is given by the smallest value of |π/2 − α4| that yields a distinction between the two models. Corresponding to the discussion in Sec. 2.9, we use three different values f… view at source ↗
Figure 7
Figure 7. Figure 7: The four-top (pp → ttt¯t¯) cross-section as a function of α4 for the 2HDMS. As vertical lines we show the N2HDM cross-section (dotted line) and the corresponding 1 (2) σ uncertainty band in yellow (green). The other parameters are chosen according to our benchmark scenario, see Tab. 2. Here σ 2HDMS,N2HDM s and σb are the signal and background cross-sections. In addition, ϵs and ϵb are the detection efficie… view at source ↗
Figure 8
Figure 8. Figure 8: α4 limits in the mA-tan β parameter space around our benchmark scenario as given in Tab. 2 according to the plane shown in Fig. 2a with ∆ma = mAD − mAS = 100 GeV for α4 < (>) π/2 in the left (right) plot. (a) (b) [PITH_FULL_IMAGE:figures/full_fig_p025_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: α4 limits in the mA-tan β parameter space as in [PITH_FULL_IMAGE:figures/full_fig_p025_9.png] view at source ↗
Figure 10
Figure 10. Figure 10: α4 limits in the mA-tan β parameter space around our benchmark scenario as given in Tab. 2 according to the plane shown in Fig. 2b with maS = 500 GeV for α4 < (>) π/2 in the left (right) plot. 25 [PITH_FULL_IMAGE:figures/full_fig_p026_10.png] view at source ↗
Figure 11
Figure 11. Figure 11: SM single and di-Higgs production cross sections at e +e − colliders as a function of √ s = 500 GeV and Pe−/e+ = −80%/ + 30%. 4.2 Di-Higgs final states at √s = 500 GeV In this section we discuss the various di-Higgs production channels relevant in the scenarios with a h95, i.e. describing the excesses at 95 GeV, see Sec. 1. In the N2HDM and 2HDMS models, we have three CP-even Higgs bosons, h1,2,3. Consequ… view at source ↗
Figure 12
Figure 12. Figure 12: Diagrams of the process e +e − → Zhihj in the N2HDM and 2HDMS. (e.g., masses and mixing matrices) are provided by SPheno-4.0.5 [47, 48]. The respective model files were generated using SARAH-4.14.3 [62–64]. To examine the impact of the CP-odd mixing angle α4 on the distinction of the two models (the “α4 limits”), we study the benchmark point given in Tab. 2. As in our benchmark scenario the h3 is too heav… view at source ↗
Figure 13
Figure 13. Figure 13: Cross-section for e +e − → Zh2h2 in the N2HDM and 2HDMS. The 1 and 2 σ regions of the N2HDM are colored yellow and green respectively. di-Higgs production Zh2h2 in the 2HDMS and N2HDM including the uncertainty bands of the N2HDM prediction according to our uncertainty estimate. For this studied parameter point, the models differ by less than 1 σ, which is in total agreement with the previous analytical di… view at source ↗
Figure 14
Figure 14. Figure 14: Cross-section for e +e − → Zh1h2 in the N2HDM and 2HDMS. The 1 and 2 σ regions of the N2HDM are colored yellow and green respectively. it is possible to determine a limit on α4 where one can distinguish both models on a 2 σ level. For the opposite side, π 2 < α4 < 3π 2 , we observe only weak deviations. Here the THCs are small, hence the total cross-sections is dominated by background processes (see [PIT… view at source ↗
Figure 15
Figure 15. Figure 15: Cross-section for e +e − → Zh1h1 in the N2HDM and 2HDMS. The 1 and 2 σ regions of the N2HDM are colored yellow and green respectively. observe an almost vanishing cross-section for the N2HDM. On the other hand, in the 2HDMS the additional terms (as detailed in Eq. (51)) can lead to large differences in the di-Higgs cross-sections thus 2 σ limits on α4 close to the N2HDM limit of the 2HDMS are found 31 [P… view at source ↗
Figure 16
Figure 16. Figure 16: ∆scombined for different ma1 . The 1 σ and 2 σ ranges are colored in yellow and green respectively. study in the four top case at the HL-LHC. We study the different 2HDMS scenarios with ∆ma = {50, 100, 150, 200} GeV and determine the α4 limits (corresponding to a model distrinction at the level of 2 σ) by computing the cross-section for the processes e +e − → Zh2h2 , e+e − → Zh1h2 , e+e − → Zh1h1 . (100) … view at source ↗
Figure 17
Figure 17. Figure 17: mA-tan β plane for α4 < (>)π/2 in the left (right) plot. The hatched areas are excluded, the color code indicates the value of the α4 limits (at 2 σ), where in the horizontal red lined areas no α4 limit was found. The parameters are chosen according to our benchmark scenario, see Tab. 2. maD is varied, with ∆ma = 50 GeV. (a) α4 limits for α4 < π/2, ∆ma = 100 GeV. (b) α4 limits for α4 > π/2, ∆ma = 100 GeV … view at source ↗
Figure 18
Figure 18. Figure 18: mA-tan β plane for α4 < (>)π/2 in the left (right) plot. The hatched areas are excluded, the color code indicates the value of the α4 limits (at 2 σ), where in the horizontal red lined areas no α4 limit was found. The parameters are chosen according to our benchmark scenario, see Tab. 2. maD is varied, with ∆ma = 100 GeV. 34 [PITH_FULL_IMAGE:figures/full_fig_p035_18.png] view at source ↗
Figure 19
Figure 19. Figure 19: mA-tan β plane for α4 < (>)π/2 in the left (right) plot. The hatched areas are excluded, the color code indicates the value of the α4 limits (at 2 σ), where in the horizontal red lined areas no α4 limit was found. The parameters are chosen according to our benchmark scenario, see Tab. 2. maD is varied, with ∆ma = 150 GeV. (a) α4 limits for α4 < π/2, ∆ma = 200 GeV. (b) α4 limits for α4 > π/2, ∆ma = 200 GeV… view at source ↗
Figure 20
Figure 20. Figure 20: mA-tan β plane for α4 < (>)π/2 in the left (right) plot. The hatched areas are excluded, the color code indicates the value of the α4 limits (at 2 σ), where in the horizontal red lined areas no α4 limit was found. The parameters are chosen according to our benchmark scenario, see Tab. 2. maD is varied, with ∆ma = 200 GeV. 35 [PITH_FULL_IMAGE:figures/full_fig_p036_20.png] view at source ↗
Figure 21
Figure 21. Figure 21: The 1 σ, 2 σ α4 limits for different vS, ma1 (see text). The labels “3” and “4” correspond to the two parameter regions labelled as such in [PITH_FULL_IMAGE:figures/full_fig_p038_21.png] view at source ↗
Figure 22
Figure 22. Figure 22: Log likelihood plot for Lint = 2 ab−1 (solid red, as evaluated in Ref. [67]) and Lint = 4 ab−1 (dashed red). The uncertainty is given by χ 2 min + 1. For simplicity, we are considering only symmetrical uncertainties. for Lint = 2 ab−1 and Lint = 4 ab−1 is shown in [PITH_FULL_IMAGE:figures/full_fig_p044_22.png] view at source ↗
Figure 23
Figure 23. Figure 23: Rescaled uncertainties for the cross-sections σ(Zhihj ) including the signal and back￾ground rates from the ILD for Lint = 2 ab−1 and Lint = 4 ab−1 in blue and the uncertainties given by the Poisson statistic in green. ILD simulations appears to approximately follow the green Poisson curve, which would be the uncertainty in a perfect detector without any background, with an offset that accounts for such i… view at source ↗

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