arxiv: 2604.16679 · v1 · submitted 2026-04-17 · ✦ hep-ph

Recognition: unknown

Probing Flavor-Violating Higgs Decays in the Type-III Two-Higgs-Doublet Model at the LHC and HL-LHC

A. Rosado, M. L. Fern\'andez-P\'erez, S. Rosado-Navarro

Authors on Pith no claims yet

Pith reviewed 2026-05-10 07:35 UTC · model grok-4.3

classification ✦ hep-ph

keywords Type-III Two-Higgs-Doublet ModelFlavor-violating Higgs decaysLHC phenomenologyCharged HiggsNeutral HiggsDiscovery potential

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The pith

Neutral and heavy charged flavor-violating Higgs decays in the Type-III two-Higgs-doublet model can exceed 5σ significance at the LHC with 300 fb^{-1} of data.

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

The paper compares three flavor-violating Higgs decay modes in the Type-III Two-Higgs-Doublet Model at the 14 TeV LHC. It finds that the neutral Higgs decaying to top and charm quarks, along with the heavy charged Higgs decaying to top and bottom, provide the most robust signals. These channels include regions where the statistical significance surpasses 5 standard deviations already at 300 inverse femtobarns. The light charged Higgs to charm-bottom is harder to observe due to large QCD backgrounds. This work highlights which channels offer the best chance to discover or constrain this model at current and future LHC runs.

Core claim

Using a common cut-based analysis with realistic detector simulation, the study shows a phenomenological hierarchy among the signatures: the neutral mode H → t c-bar and the heavy charged mode H± → t b-bar emerge as the most robust, with parameter regions exceeding the 5σ benchmark at 300 fb^{-1}. The light charged channel H± → c b-bar is more sensitive to the event-selection strategy because of large QCD backgrounds, though one competitive benchmark survives. The results identify the neutral and heavy charged channels as the most promising targets for discovery-oriented searches and for constraining the Type-III 2HDM parameter space at the LHC and HL-LHC. All quoted significances are purely

What carries the argument

A comparative cut-based analysis of three specific flavor-violating decay channels: neutral Higgs to top-charm, charged Higgs to charm-bottom, and charged Higgs to top-bottom, performed with detector simulation.

Load-bearing premise

The reported significances rely on statistical errors alone without accounting for systematic uncertainties or detailed background modeling.

What would settle it

A complete experimental analysis of the neutral Higgs to top-charm channel using 300 fb^{-1} of 14 TeV data that finds no excess above background expectations would falsify the existence of parameter regions with 5σ significance.

Figures

Figures reproduced from arXiv: 2604.16679 by A. Rosado, M. L. Fern\'andez-P\'erez, S. Rosado-Navarro.

**Figure 4.** Figure 4: FIG. 4. Neutral benchmark with [PITH_FULL_IMAGE:figures/full_fig_p012_4.png] view at source ↗

**Figure 2.** Figure 2: FIG. 2. Neutral benchmark with [PITH_FULL_IMAGE:figures/full_fig_p012_2.png] view at source ↗

**Figure 6.** Figure 6: FIG. 6. Neutral benchmark with [PITH_FULL_IMAGE:figures/full_fig_p013_6.png] view at source ↗

**Figure 7.** Figure 7: FIG. 7. Neutral benchmark with [PITH_FULL_IMAGE:figures/full_fig_p013_7.png] view at source ↗

**Figure 8.** Figure 8: FIG. 8. Neutral benchmark with [PITH_FULL_IMAGE:figures/full_fig_p013_8.png] view at source ↗

**Figure 12.** Figure 12: FIG. 12. Charged benchmark with [PITH_FULL_IMAGE:figures/full_fig_p014_12.png] view at source ↗

**Figure 13.** Figure 13: FIG. 13. Charged benchmark with [PITH_FULL_IMAGE:figures/full_fig_p014_13.png] view at source ↗

**Figure 14.** Figure 14: FIG. 14. Charged benchmark with [PITH_FULL_IMAGE:figures/full_fig_p014_14.png] view at source ↗

**Figure 18.** Figure 18: FIG. 18. Charged benchmark with [PITH_FULL_IMAGE:figures/full_fig_p015_18.png] view at source ↗

**Figure 19.** Figure 19: FIG. 19. Charged benchmark with [PITH_FULL_IMAGE:figures/full_fig_p015_19.png] view at source ↗

read the original abstract

We present a comparative collider study of three flavor-violating Higgs signatures in the Type-III Two-Higgs-Doublet Model (\ddHmIII) at \(\sqrt{s}=14\)~TeV: \(pp \to H \to t\bar{c} \ (\bar{t}c)\), \(pp \to H^\pm \to c\bar{b} \ (\bar{c}b)\), and \(pp \to H^\pm \to t\bar{b} \ (\bar{t}b)\). Using a common cut-based analysis and realistic detector simulation, we identify a clear phenomenological hierarchy. The neutral mode and the heavy charged mode emerge as the most robust signatures, containing parameter regions that already exceed the \(5\sigma\) benchmark at an integrated luminosity of \(300~\text{fb}^{-1}\). In contrast, the light charged channel \(H^{\pm}\to c\bar{b}\) is considerably more sensitive to the event-selection strategy because of large QCD backgrounds, although one competitive benchmark survives. Our results single out the neutral and heavy charged flavor-violating channels as the most promising targets for discovery-oriented searches and for constraining the \ddHmIII\ parameter space at the LHC and HL-LHC. All quoted significances are purely statistical and do not include systematic uncertainties.

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.

Desk Editor's Note private letter to a colleague

The paper ranks three flavor-violating Higgs channels in Type-III 2HDM and flags the neutral and heavy-charged modes as most promising at 300 fb^{-1}, but only with statistical significances.

read the letter

The paper ranks three flavor-violating Higgs channels in the Type-III two-Higgs-doublet model and concludes that the neutral H to top-charm and heavy charged H-plus to top-bottom are the strongest, with some points already above 5 sigma at 300 fb inverse at 14 TeV. The light charged channel to charm-bottom is less reliable due to QCD backgrounds. What stands out is the side-by-side comparison using the same analysis cuts and detector simulation for all three. This gives a clear phenomenological hierarchy that experimentalists can use to prioritize searches. The authors are upfront that everything is statistical significance only. The soft spot is exactly that omission of systematics. In these multi-jet final states, things like jet energy scale, b-tagging efficiencies, and background normalizations usually matter a lot and can reduce significances substantially. The abstract already points out how sensitive the light channel is to the event selection, so the same caution applies to the others. Without those numbers, the robustness claim is preliminary. This kind of work is aimed at people doing LHC phenomenology on extended Higgs models. It does not break new theoretical ground but supplies useful benchmarks for where to look. The setup follows standard practices in the field with no red flags in the approach described. I would take this to a reading group on collider BSM if we were discussing 2HDM variants. I would not cite it myself in the next year unless referencing specific numbers for a search proposal. It deserves peer review because the comparative study is concrete and the community can benefit from the ranking once the systematics are addressed.

Referee Report

1 major / 1 minor

Summary. The paper conducts a comparative collider study of three flavor-violating Higgs decay signatures in the Type-III Two-Higgs-Doublet Model at 14 TeV: the neutral mode pp → H → t c̄ (t̄ c), the light charged mode pp → H± → c b̄ (c̄ b), and the heavy charged mode pp → H± → t b̄ (t̄ b). Employing a common cut-based analysis together with realistic detector simulation, the work identifies a phenomenological hierarchy in which the neutral and heavy charged channels contain parameter regions (masses, tan β, flavor-violating couplings) that yield statistical significances exceeding 5σ already at 300 fb^{-1}, while the light charged channel is more sensitive to the choice of event selection because of large QCD backgrounds. The study concludes that the neutral and heavy charged modes are the most promising targets for discovery searches and for constraining the model at the LHC and HL-LHC; all quoted significances are stated to be purely statistical and exclude systematic uncertainties.

Significance. If the reported statistical significances survive the inclusion of realistic systematic uncertainties on backgrounds and detector effects, the paper would usefully highlight the neutral H → t c̄ and heavy H± → t b̄ channels as the most robust probes of flavor violation in the Type-III 2HDM, thereby guiding experimental searches and providing concrete targets for parameter-space constraints at current and future LHC luminosities. The explicit comparative analysis across the three modes and the identification of a clear hierarchy constitute a constructive contribution to the phenomenology of extended Higgs sectors.

major comments (1)

[Abstract] Abstract: The central claim that parameter regions in the neutral H → t c̄ and heavy H± → t b̄ channels already exceed the 5σ benchmark at an integrated luminosity of 300 fb^{-1} rests exclusively on purely statistical significances. The final states involve jets, b-tags, and missing energy or leptons, where the dominant backgrounds are QCD multijet and t t̄ production; typical experimental systematics (jet-energy scale, b-tagging efficiency, luminosity, and background normalization) are 10–30 %. The manuscript itself notes that the light charged channel is sensitive to the event-selection strategy precisely because of large QCD backgrounds, indicating that analogous modeling uncertainties could affect the neutral and heavy charged channels and potentially bring the significances below 5σ, thereby weakening the assertion that these modes are the 'most robust'.

minor comments (1)

[Abstract] Abstract: The explicit disclaimer that 'all quoted significances are purely statistical and do not include systematic uncertainties' should be repeated in the conclusions and in any summary tables or figures that present the 5σ results, to prevent readers from overlooking the limitation.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the constructive and detailed review of our manuscript. We address the major comment on systematic uncertainties point by point below and outline the revisions we will implement.

read point-by-point responses

Referee: [Abstract] Abstract: The central claim that parameter regions in the neutral H → t c̄ and heavy H± → t b̄ channels already exceed the 5σ benchmark at an integrated luminosity of 300 fb^{-1} rests exclusively on purely statistical significances. The final states involve jets, b-tags, and missing energy or leptons, where the dominant backgrounds are QCD multijet and t t̄ production; typical experimental systematics (jet-energy scale, b-tagging efficiency, luminosity, and background normalization) are 10–30 %. The manuscript itself notes that the light charged channel is sensitive to the event-selection strategy precisely because of large QCD backgrounds, indicating that analogous modeling uncertainties could affect the neutral and heavy charged channels and potentially bring the significances below 5σ, thereby weakening the assertion that these modes are the 'most robust'.

Authors: We agree that systematic uncertainties must be considered for any realistic assessment of discovery reach and thank the referee for emphasizing this. Our analysis is a cut-based phenomenological study using Delphes fast simulation; we already state explicitly in the abstract and throughout the text that all significances are purely statistical and exclude systematics. The comparative hierarchy we report arises because the neutral H → tc and heavy H± → tb channels have substantially lower QCD multijet backgrounds and higher signal-to-background ratios than the light charged mode under the same selection criteria. While 10–30 % systematics could reduce absolute significances, the relative robustness of the neutral and heavy channels is expected to persist. We will revise the abstract to make the statistical-only disclaimer more prominent at the outset and add a short paragraph in the conclusions discussing the likely impact of typical experimental systematics, noting that the light charged channel remains the most vulnerable. These changes constitute a partial revision: we clarify limitations without altering the core phenomenological conclusions or the identification of the most promising channels. revision: partial

Circularity Check

0 steps flagged

No circularity: collider study uses independent Monte Carlo simulation and cut-based analysis

full rationale

The paper's central results are obtained by generating signal and background events with standard Monte Carlo tools, applying a common cut-based selection, and performing a realistic detector simulation to compute expected significances in three flavor-violating channels. These significances are derived from Poisson statistics on the post-cut yields at fixed luminosities; no parameter is fitted to the target observables and then re-used as a prediction, no self-citation supplies a load-bearing uniqueness theorem, and no ansatz or renaming reduces the claimed hierarchy to an input by construction. The analysis chain is externally falsifiable via independent event generators and detector models, satisfying the criteria for a self-contained, non-circular derivation.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 0 invented entities

The central claim depends on the validity of the Type-III 2HDM Yukawa structure, the accuracy of Monte Carlo background modeling, and the choice of a common set of cuts; these are standard domain assumptions rather than new entities.

free parameters (1)

Type-III 2HDM parameters (masses, tan beta, flavor-violating couplings)
The study scans regions of the model parameter space to find points that exceed 5σ; exact values are not listed in the abstract.

axioms (1)

domain assumption Type-III 2HDM allows tree-level flavor-changing neutral currents via non-diagonal Yukawa matrices
The entire analysis presupposes this extension of the Standard Model.

pith-pipeline@v0.9.0 · 5555 in / 1439 out tokens · 45794 ms · 2026-05-10T07:35:04.067360+00:00 · methodology

discussion (0)

Reference graph

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abenchmark-dependentM(jj)windowcenteredon mH. For this neutral channel, the quantity denoted by M(jj)should be understood operationally as the re- constructed dijet invariant-mass observable used in the MadAnalysis5implementation as the final discrimina- tor. In other words,M(jj)labels the jet-pair invariant- mass variable entering the last signal-region ...
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Neutral channel:pp→H→t¯c+ ¯tc FIG. 1. Neutral benchmark withmH = 180GeV,tanβ= 0.1, andχ tc = 10. FIG. 2. Neutral benchmark withmH = 200GeV,tanβ= 1, andχ tc = 5. FIG. 3. Neutral benchmark withmH = 220GeV,tanβ= 0.1, andχ tc = 1. FIG. 4. Neutral benchmark withmH = 240GeV,tanβ= 0.1, andχ tc = 1. FIG. 5. Neutral benchmark withmH = 280GeV,tanβ= 0.1, andχ tc = 0...
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Light charged channel:pp→H ± →c ¯b+ ¯cb FIG. 9. Improved light charged-Higgs benchmark with mH± = 110GeV,tanβ= 5, andχ cb = 5, showing the fi- nal dijet mass distribution in the selected90< M(jj)<130 GeV region
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Heavy charged channel:pp→H ± →t ¯b+ ¯tb FIG. 10. Charged benchmark withmH± = 300GeV,tanβ= 1, andχ= 10. FIG. 11. Charged benchmark withmH± = 300GeV,tanβ= 20, andχ= 10. 14 FIG. 12. Charged benchmark withmH± = 350GeV,tanβ= 1, andχ= 10. FIG. 13. Charged benchmark withmH± = 350GeV,tanβ= 20, andχ= 10. FIG. 14. Charged benchmark withmH± = 400GeV,tanβ= 1, andχ= 1...
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