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arxiv: 2606.10576 · v1 · pith:KCLADHJ3new · submitted 2026-06-09 · ✦ hep-ph

Constraints on the Higgs-gluon effective coupling through h to γγ decays at the LHC

A. Mohamed-Meziani This is my paper

Pith reviewed 2026-06-27 12:35 UTC · model grok-4.3

classification ✦ hep-ph
keywords Higgs bosoneffective couplingdiphoton decayLHCATLASkappa_gconstraintssimulation
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The pith

Simulations of the diphoton Higgs decay constrain the effective Higgs-gluon coupling modifier |κ_g| to the interval [0.80, 1.20] at 68% CL.

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

The paper generates simulated events for the process pp → h → γγ at 13 TeV while varying the modifier κ_g of the Higgs-gluon effective coupling. It confirms that the production cross section after detector cuts scales precisely with κ_g squared. Matching the simulated rates to the published ATLAS Run 2 likelihood profile then yields explicit confidence intervals on |κ_g|. These intervals agree with the official ATLAS and CMS combined results. The study thereby validates both the chosen model implementation and the use of a fast simulation chain for extracting Higgs coupling bounds.

Core claim

In the HPOprodMFV_UFO framework the cross section σ(pp → h → γγ) is proportional to κ_g². Events generated with MadGraph5_aMC@NLO for |κ_g| values from 0.6 to 1.4, showered with Pythia8, passed through an ATLAS-like Delphes detector, and analysed with MadAnalysis5 produce a Standard Model cross section of 0.04067 ± 0.00008 pb after selection cuts. Direct comparison of these cross sections with the ATLAS Run 2 likelihood profile from HEPData gives the intervals |κ_g| ∈ [0.80, 1.20] at 68% CL and |κ_g| ∈ [0.70, 1.30] at 95% CL, reproducing the official ATLAS and CMS combinations.

What carries the argument

The dimensionless modifier κ_g that rescales the effective Higgs-gluon vertex, causing the diphoton production cross section to scale as κ_g².

If this is right

  • The derived |κ_g| intervals are consistent with the official ATLAS and CMS combined constraints.
  • The quadratic scaling σ ∝ κ_g² holds to high precision inside the simulated range 0.6–1.4.
  • A fast detector simulation chain can be used to explore Higgs effective couplings in the diphoton channel.
  • The HPOprodMFV_UFO model implementation is validated for this process.

Where Pith is reading between the lines

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

  • The same simulation workflow could be applied to other Higgs production modes to test consistency across channels.
  • If the quadratic dependence continues to hold at higher precision, it supports treating the Higgs-gluon interaction as a simple rescaling of the Standard Model vertex.
  • Updated LHC datasets with larger integrated luminosity would tighten the same intervals using identical comparison methods.

Load-bearing premise

The MadGraph-Pythia-Delphes-MadAnalysis simulation chain reproduces the true dependence of the observed cross section on κ_g without introducing extra systematic uncertainties beyond those already present in the ATLAS likelihood.

What would settle it

An independent measurement of the pp → h → γγ cross section lying outside the band predicted by the quadratic scaling for |κ_g| values between 0.70 and 1.30 at 95% CL would falsify the extracted intervals.

read the original abstract

We present a detailed study of the $pp\to h\to\gamma\gamma$ process in the HPOprodMFV\_UFO model framework, focusing on the Higgs-gluon effective coupling modifier, $\kappa_g$. We generate events for 26 parameter points corresponding to $|\kappa_g|$ values ranging from 0.6 to 1.4 using MadGraph5\_aMC@NLO simulations at 13 TeV with NNPDF3.1 parton distribution functions. These events are processed through Pythia8 for parton showering and hadronisation. This is followed by a fast detector simulation using Delphes with an ATLAS-like configuration and analysis with MadAnalysis5. We verify the expected quadratic scaling, $\sigma(pp \to h \to \gamma\gamma) \propto \kappa_g^2$, with high precision, confirming the consistency of our simulation framework. The Standard Model cross section after the application of selection cuts is found to be $\sigma_{\mathrm{SM}} = 0.04067 \pm 0.00008$ pb. By comparing our results with the ATLAS Run 2 likelihood profile from HEPData (HEPData:ins1851456), we derive constraints on $|\kappa_g|$: \begin{align*} |\kappa_g| &\in [0.80,\, 1.20] \quad \text{at 68\% CL}, |\kappa_g| &\in [0.70,\, 1.30] \quad \text{at 95\% CL},. \end{align*} These results are in excellent agreement with the official ATLAS and CMS combinations. Our analysis validates the HPOprodMFV\_UFO model implementation and demonstrates the effectiveness of simplified simulations in exploring Higgs couplings in the diphoton channel. }

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

1 major / 2 minor

Summary. The manuscript simulates the pp→h→γγ process at 13 TeV in the HPOprodMFV_UFO framework for 26 values of |κ_g| between 0.6 and 1.4. Events are generated with MadGraph5_aMC@NLO + NNPDF3.1, showered with Pythia8, passed through Delphes (ATLAS-like detector) and analyzed with MadAnalysis5. The quadratic scaling σ ∝ κ_g² is verified to high precision; the SM cross section after cuts is reported as 0.04067 ± 0.00008 pb. Constraints |κ_g| ∈ [0.80, 1.20] (68% CL) and [0.70, 1.30] (95% CL) are obtained by mapping the simulated post-cut cross sections onto the ATLAS Run 2 likelihood profile from HEPData (ins1851456) and are stated to agree with official ATLAS/CMS combinations.

Significance. If the Delphes+MadAnalysis5 selection efficiencies match those implicit in the HEPData likelihood, the work validates the UFO model implementation and shows that a simplified simulation chain can reproduce the expected quadratic dependence. The numerical constraints themselves add little new information because they are obtained by rescaling to an existing experimental likelihood rather than performing an independent analysis; their primary value would lie in the cross-check of the simulation pipeline.

major comments (1)
  1. [Abstract] Abstract (constraint derivation paragraph): the quoted |κ_g| intervals are obtained by assuming that the post-selection cross sections from the MadGraph+Pythia+Delphes+MadAnalysis5 chain are directly proportional to the signal strengths entering the HEPData likelihood profile, with identical acceptance and efficiency. No comparison of kinematic distributions, photon identification efficiencies, isolation criteria, or cut efficiencies against the ATLAS analysis is presented; any mismatch would rescale the effective yield and invalidate the intervals. This assumption is load-bearing for the central claim.
minor comments (2)
  1. [Abstract] Abstract: the displayed align* environment ends with a trailing comma after the 95% CL line.
  2. [Analysis section] The manuscript should state the precise definition of the selection cuts applied in MadAnalysis5 and confirm that they reproduce the ATLAS diphoton analysis cuts used to construct the HEPData profile.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the careful reading of our manuscript and the constructive feedback. We respond to the major comment below.

read point-by-point responses

  1. Referee: [Abstract] Abstract (constraint derivation paragraph): the quoted |κ_g| intervals are obtained by assuming that the post-selection cross sections from the MadGraph+Pythia+Delphes+MadAnalysis5 chain are directly proportional to the signal strengths entering the HEPData likelihood profile, with identical acceptance and efficiency. No comparison of kinematic distributions, photon identification efficiencies, isolation criteria, or cut efficiencies against the ATLAS analysis is presented; any mismatch would rescale the effective yield and invalidate the intervals. This assumption is load-bearing for the central claim.

    Authors: We agree that the mapping of our simulated post-cut cross sections onto the HEPData likelihood profile assumes comparable acceptance and efficiency between the Delphes+MadAnalysis5 chain and the ATLAS analysis. Our simulation employs the standard ATLAS-like Delphes card together with a selection designed to approximate the experimental photon identification and isolation requirements. The fact that the resulting |κ_g| intervals closely reproduce the official ATLAS and CMS combinations provides an a posteriori consistency check on the overall normalization. The verification of quadratic scaling σ ∝ κ_g² is independent of this absolute normalization and remains robust. In the revised manuscript we will add an explicit statement of this assumption in the abstract and analysis sections, together with a short discussion of the simulation fidelity and its implications for the derived constraints. revision: yes

Circularity Check

0 steps flagged

No circularity: constraints obtained via external HEPData likelihood comparison

full rationale

The paper's derivation chain consists of (1) generating MadGraph events at discrete κ_g points, (2) processing through Pythia8+Delphes+MadAnalysis5, (3) verifying σ ∝ κ_g² (a standard SM expectation, not a fit), and (4) mapping the resulting σ(κ_g) values onto the external ATLAS Run 2 likelihood profile published in HEPData (ins1851456). Step (4) is a direct comparison to an independent experimental result; the quoted intervals are therefore read off from that external profile rather than being constructed from the simulation inputs themselves. No self-citation, self-definitional mapping, fitted parameter renamed as prediction, or ansatz smuggling appears in the text. The procedure is a conventional parameter constraint against an external benchmark and is self-contained against that benchmark.

Axiom & Free-Parameter Ledger

1 free parameters · 2 axioms · 0 invented entities

The central claim rests on the correctness of the HPOprodMFV_UFO model implementation and the fidelity of the Monte Carlo detector simulation chain; these are domain assumptions with no independent verification supplied in the abstract. No new particles or forces are introduced.

free parameters (1)
  • kappa_g
    The effective coupling modifier is scanned over 26 discrete values between 0.6 and 1.4 to map the cross-section dependence and extract limits.
axioms (2)
  • domain assumption The HPOprodMFV_UFO model correctly encodes the effective Higgs-gluon coupling modification.
    Event generation is performed inside this specific UFO model framework.
  • domain assumption The Delphes ATLAS-like detector simulation plus MadAnalysis5 selection accurately reproduces experimental efficiencies and acceptances for the diphoton final state.
    Fast simulation is used to obtain the post-cut cross sections that are compared to data.

pith-pipeline@v0.9.1-grok · 5868 in / 1649 out tokens · 27005 ms · 2026-06-27T12:35:37.417497+00:00 · methodology

discussion (0)

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Reference graph

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