{"id":"7b4f0e3b-150b-4d90-ab58-c913d19d5398","arxiv_id":"2603.03404","paper_version":1,"verdict":"REJECT","confidence":"MODERATE","novelty_score":2.0,"correctness_risk":"high","formal_verification":"none","parameter_count":2,"one_line_summary":"A LO+MLM MadGraph simulation of tHq and tWH production, scaled by K-factors to match NLO benchmarks, gives 85.9 fb in the SM and 380 fb for inverted top Yukawa coupling - a smaller enhancement than the ~890 fb quoted from ATLAS literature.","lead":"Using MadGraph simulations of Higgs-plus-single-top production, this paper reports Standard Model cross sections close to ATLAS values and an enhanced rate when the top Yukawa coupling sign is flipped. The enhancement is presented as support for an inverted-coupling explanation of a mild ATLAS excess, but the agreement is partly engineered by K-factors tuned to the benchmarks being compared.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The paper's claimed quantitative support is contradicted by its own Eq. (7): the ITC rate after applying SM K-factors is 380 fb, not the ~890 fb NLO benchmark, so the ATLAS-excess interpretation is unsupported unless ITC K-factors differ—which is exactly the unproven assumption.","rationale":"The paper is a phenomenological simulation study that attempts to validate a LO+MLM MadGraph setup against NLO tH cross-sections using K-factors, and then to use that setup to estimate the rate and kinematics for kappa_t=-1, arguing consistency with the ATLAS excess. For the central claim to hold, the K-factors must be transferable from the SM to the inverted-coupling scenario. The weakest assumption identified by the reader is exactly that transfer: there is no evidence that NLO corrections are independent of the sign of the top Yukawa coupling. I agree with that diagnosis, and I would add that the paper's own Eq. (7) provides a concrete internal inconsistency: applying the SM K-factors to ITC gives 380.4 fb, while the paper quotes ~890 fb as the NLO ITC benchmark in Table 2. The paper explicitly acknowledges the discrepancy but does not resolve it; the conclusion nonetheless claims quantitative support. That is an internal numerical contradiction in the central argument, not a mere disagreement with the prevailing theoretical consensus. A single, well-defined NLO calculation of the ITC K-factors would settle whether the discrepancy reflects a missing large K-factor or an incorrect benchmark. The SM validation is also weak because the K-factors are fitted to reproduce the NLO values, making the 4% agreement non-predictive, but even granting that validation, the ITC extrapolation remains unjustified. No code or configuration files are provided, which further limits verification, but the decisive issue is the absent ITC K-factor calculation. Therefore the reader's REJECT verdict is appropriate and does not need to be changed.","tokens_in":19396,"tokens_out":5184,"duration_ms":46041,"concrete_test":"Run a fixed-order NLO calculation (e.g., MadGraph5_aMC@NLO with the same flavour schemes, NNPDF sets, dynamic scales, and ATLAS-inspired cuts used in this paper) for kappa_t=-1 for both tHq and tWH, and compute K_ITC = sigma_NLO(kappa_t=-1) / sigma_LO+MLM(kappa_t=-1). Compare these with the SM values 1.5 and 0.7. Concretely, if the paper's ITC LO+MLM cross-sections are correct (227 fb for tHq, 57 fb for tWH), then reaching the quoted NLO ITC cross-sections of ~740 fb and ~150 fb would require K_ITC,tHq ~ 3.26 and K_ITC,tWH ~ 2.63. If a direct NLO computation confirms K-factors near the SM values, then Eq. (7) stands and the claimed agreement with the ~890 fb benchmark and the ATLAS excess is contradicted by the paper's own numbers. If the direct computation yields substantially different K-factors, the paper's Eq. (7) is wrong as written and the central quantitative claim collapses. Eith","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim, stated in Sections 3.4 and 5, is that a LO+MLM simulation chain with K-factors provides a validated surrogate for NLO tH predictions and that the inverted-coupling (ITC) result quantitatively supports the ATLAS excess. This requires transferring the SM K-factors K_tHq=1.5 and K_tWH=0.7 to the kappa_t=-1 scenario. The paper offers no evidence that NLO QCD corrections are independent of the sign of the top Yukawa coupling; the K-factors could be different for ITC because the relative weights of interference contributions change. This is not a merely formal worry: applying those SM K-factors to the ITC LO+MLM cross-sections (227 fb and 57 fb) yields Eq. (7): sigma_NLO,ITC_tH ~ 380.4 fb. Table 2 quotes the NLO ITC prediction as ~890 fb. The paper acknowledges this discrepancy but leaves it unresolved, then concludes that the results 'quantitatively support' the interpretation of the ATLAS excess. A 380.4 fb prediction is 2.3 times below the 890 fb benchmark used to infer the ATLAS ITC signal strength (mu_ITC=1.2+/-...), so the claimed quantitative support fails. Either the ITC K-factors must be much larger (roughly 3.3 for tHq and 2.6 for tWH to reach the quoted 740 fb and 150 fb), or the quoted NLO benchmark is inappropriate. In neither case is the assumption of unchanged K-factors tenable. Thus the central quantitative conclusion rests entirely on an unvalidated transfer, and the paper's own Eq. (7) is evidence against that transfer.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper uses MadGraph5_aMC@NLO at LO+MLM to simulate tHq production in the 4FS and tWH production in the 5FS at sqrt(s)=13 and 14 TeV, with ATLAS-inspired event selection. It introduces K-factors K_tHq ~ 1.57 and K_tWH ~ 0.69 that normalize the LO+MLM rates to the quoted NLO SM benchmarks 74.3 fb and 15.2 fb, and then reports a total SM cross-section of ~85.9 fb, which it presents as validation against the ATLAS SM expectation of 89.5 fb. For the inverted top Yukawa coupling (ITC, kappa_t=-1), the same K-factors are applied to LO+MLM rates of 227 fb and 57 fb, yielding Eq. (7): sigma_NLO,ITC_tH ~ 380.4 fb. The paper nevertheless concludes that the results quantitatively support the interpretation of the ATLAS tH excess in terms of an inverted top-Higgs coupling. Several kinematic distributions are also presented for the ITC scenario.","tokens_in":19828,"tokens_out":5032,"duration_ms":43171,"significance":"If the central claims were valid, the paper would offer a computationally cheap LO+MLM surrogate for NLO tH predictions and would provide a quantitative explanation of the ATLAS tH excess via kappa_t=-1. The use of established Monte Carlo tools, the explicit documentation of flavour-scheme choices, and the presentation of differential distributions are useful elements. However, the validation strategy is circular, and the paper's own Eq. (7) gives an ITC rate that is more than a factor of two below the quoted NLO ITC benchmark. Because the main conclusions rest on these two points, the paper's central claims are not supported by its own equations.","major_comments":[{"comment":"The claimed SM validation is constructed. K_tHq ~ 1.57 and K_tWH ~ 0.69 are defined as exactly the ratios that make the LO+MLM rates 0.047 pb and 0.022 pb reproduce the quoted NLO benchmarks 74.3 fb and 15.2 fb in Eqs. (1)-(2). The relative difference of -4.0% computed in Eq. (5) is therefore a restatement of this normalization, not an independent check. To validate the LO+MLM chain, the K-factors would need to come from an independent source, e.g., fixed-order NLO calculations performed for the same setup, with the comparison to 89.5 fb then being a genuine test.","section":"Sec. 3.3-3.4, Eqs. (1)-(5)"},{"comment":"The ITC result is internally inconsistent. Applying the SM K-factors to the ITC LO+MLM rates gives sigma_NLO,ITC_tH ~ 380.4 fb in Eq. (7), about a factor of 2.3 below the ~890 fb quoted in Table 2 (340.5 vs ~740 fb for tHq and 39.9 vs ~150 fb for tWH). The text acknowledges this discrepancy but then, in Sec. 5, concludes that the results 'quantitatively support' the ATLAS excess. A rate 2.3 times below the benchmark used to infer mu_ITC ~ 1.2 cannot be called quantitative support. Either the ITC K-factors are much larger than the SM ones, or the 890 fb benchmark is not applicable; in neither case does the analysis support the stated conclusion.","section":"Sec. 3.5, Eq. (7) vs Table 2 and Sec. 5"},{"comment":"No evidence is provided that SM K-factors apply unchanged at kappa_t=-1. NLO QCD corrections can depend on the sign of the Yukawa coupling through modified interference contributions. The large discrepancy between Eq. (7) and the quoted 890 fb is direct evidence that such dependence can be numerically important. A minimal requirement is an NLO (or NLO+PS) calculation of the tHq and tWH K-factors for kappa_t=-1 using the same setup, or a comparison with existing public NLO predictions for ITC. Without this, the label 'approximate NLO-equivalent' for Eq. (7) is unsupported, and the ITC interpretation of the ATLAS excess collapses.","section":"Sec. 3.5"}],"minor_comments":[{"comment":"The row 'pp->tHq NLO 0.028' is inconsistent with the NLO benchmark of 74.3 fb quoted in Sec. 3.1 and Table 5. The label and provenance of this entry should be clarified.","section":"Table 6"},{"comment":"References [10] and [12] are identical, and [11], [13], and [15] are identical. In-text citations to the tWH NLO calculation should use unique labels.","section":"References"},{"comment":"The phrase 'y-axis ranging from 10^2 to 0' should be rephrased as 'from 10^2 down to 0' or equivalent; as written it is ambiguous.","section":"Sec. 4, Figure 3 caption"},{"comment":"The running text 'ATLAS (arXiv:2508.14695)' should be replaced by the formal reference [7].","section":"Sec. 4, p. 14"}],"recommendation":"reject","confidential_remarks":"The paper's core findings are unsupported by its own equations. The main issues are not stylistic: the SM validation is a circular normalization exercise, and the ITC extrapolation contradicts the quoted NLO benchmark by more than a factor of two. I do not see a path to acceptance without a new NLO-based ITC calculation, an independent validation strategy for the LO+MLM chain, and a reworking of the central claims. The duplicated references and inconsistent table entries also suggest the manuscript is not yet in a form suitable for refereeing."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"The topic is a real one — tH production is one of the cleanest probes of the sign of the top Yukawa, and the ATLAS excess makes the inverted-coupling question timely — but the paper's central argument doesn't hold. The SM 'validation' is circular, and the paper's own Eq. (7) gives 380 fb for the ITC rate, less than half the 890 fb benchmark it quotes, yet the conclusion claims quantitative support for the ATLAS excess anyway.\n\nWhat it does well: the flavour-scheme discussion (4FS for tHq, 5FS for tWH) is competent, the simulation setup (MadGraph LO+MLM, NNPDF, MadAnalysis) is standard and plausibly run correctly, and the LO+MLM numbers — 47/22 fb for SM, 227/57 fb for kappa_t=-1 — are internally consistent, with enhancement factors ~4.8 and ~2.6 matching the expected switch from destructive to constructive interference. Framed honestly as a LO+MLM look at kinematic shifts under kappa_t=-1, this could be a modest but useful note.\n\nThe soft spots are structural. First, Section 3.4's 'agreement' with the NLO benchmark is a tautology: K_tHq ~ 1.57 and K_tWH ~ 0.69 are computed as ratios of the quoted NLO targets (74.3 and 15.2 fb) to the authors' own LO+MLM outputs, so the 4% offset is rounding noise, not validation. The tWH case is worse: the text quotes literature K-factors of 1.16-1.18, then adopts 0.69 — the wrong direction. The only coherent reading is that their 5FS LO baseline lives in a different phase space than the literature LO, so the literature K-factor was never applicable.\n\nSecond, the ITC extrapolation fails on its own terms. Transferring SM K-factors to kappa_t=-1 assumes NLO QCD corrections don't care about the Yukawa sign, and the transfer yields Eq. (7): 380.4 fb against the ~890 fb NLO value in Table 2. The paper acknowledges the gap in one sentence, then ignores it in the conclusion. That's a self-contradiction.\n\nMinor: the introduction promises statistical error estimation, kappa_t limits, and HL-LHC projections that never appear quantitatively; no code or configs are shipped, so the numbers can't be independently checked from the text; references [10]/[12] and [11]/[13]/[15] are duplicated.\n\nBottom line: send it to peer review and expect a reject. A referee can pin down the circular K-factor construction and the 380-vs-890 problem quickly, and the underlying question — whether the K-factors transfer to kappa_t=-1 — is worth answering. A revision that drops the 'validated surrogate' framing and presents the ITC number as a caveated LO+MLM estimate could become a small, honest contribution. As it stands, the central claim is unsupported.","headline":"Sound motivation, broken argument: the SM agreement is fitted K-factors in a circle, and Eq. (7)'s 380 fb contradicts the ~890 fb benchmark behind the claimed ATLAS-excess support.","tokens_in":20395,"tokens_out":10616,"would_cite":false,"duration_ms":100445,"reading_group":"maybe","serious_thinker":"no","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"The paper claims that an inverted top Yukawa coupling, modeled with a K-factor-corrected leading-order simulation, can explain the mild excess of single-top + Higgs events seen by ATLAS.","keywords":["top Yukawa coupling","tH production","single top + Higgs","inverted top coupling","κ_t","K-factors","LO+MLM","ATLAS excess"],"falsifier":"Compute the full NLO QCD cross section for tHq and tWH production with κ_t = -1 using the same 4FS/5FS setups and cuts as in Refs. [12,15] of the paper. If the result is close to 890 fb rather than to the paper's scaled 380 fb, the assumption that SM K-factors transfer to ITC is falsified. Alternatively, an HL-LHC measurement of the tH rate consistent with the SM would rule out the ITC explanation.","tokens_in":19209,"feed_emoji":"⚛️","tokens_out":10475,"duration_ms":76742,"temperature":0.7,"pith_summary":"The paper aims to establish two linked results. First, it argues that a leading-order MadGraph simulation with MLM jet matching, after applying flavor-scheme-dependent K-factors (1.5 for tHq, 0.7 for tWH), reproduces the next-to-leading-order Standard Model cross section for single-top + Higgs production (85.9 fb vs 89.5 fb) and the key kinematic distributions, making the simplified chain a reliable modeling tool. Second, it claims that in the inverted top Yukawa scenario (κ_t = -1), the same chain yields a strong constructive-interference enhancement (LO+MLM 284 fb, scaled to 380 fb) and harder pT tails, which the authors interpret as qualitative support for the ATLAS 2.8σ excess being due to modified top-Higgs interactions. If true, this would provide a cost-effective simulation route for tH searches and a specific new-physics interpretation of the anomaly. The paper itself notes that its scaled ITC rate of 380 fb is below the ~890 fb NLO prediction it quotes, but still treats the agreement as supportive.","feed_headline":"Sign flip in top-Higgs coupling said to explain ATLAS tH excess","feed_subtitle":"K-factor-corrected LO matches SM; flipped Yukawa sign boosts tH production and hardens pT spectra.","key_machinery":"The central mechanism is the interference between Feynman diagrams involving the top-Higgs Yukawa coupling and those mediated by W-boson exchange in tHq and tWH production: destructive in the Standard Model (κ_t = +1), constructive when the Yukawa sign is flipped (κ_t = -1). The computational machinery is a MadGraph5_aMC@NLO leading-order simulation with MLM merging, using the 4FS for tHq and 5FS for tWH, and normalized to NLO by per-process K-factors (K_tHq ≈ 1.5, K_tWH ≈ 0.7).","core_discovery":"On its own terms, the paper's central discovery is that a hybrid flavor-scheme simulation (4FS for the t-channel tHq, 5FS for tWH) at LO+MLM, corrected by multiplicative K-factors, reproduces the SM tH cross section (85.9 fb vs the ATLAS NLO reference 89.5 fb, a 4% difference) and the shapes of key observables (HT, pT(h), forward-jet η, ΔR). Applying the same prescription to the inverted coupling κ_t = -1 turns the SM's destructive interference into constructive interference, raising the LO+MLM cross section by factors of ~4.8 (tHq) and ~2.6 (tWH), and after K-factors yielding an approximate NLO-equivalent total of 380.4 fb. The authors read the rate enhancement and the harder kinematic tail","pith_inferences":["The ratio between the paper's scaled ITC prediction (380 fb, Eq. 7) and the ~890 fb NLO value it quotes from ATLAS implies that the 'quantitative support' for the ITC interpretation depends on the transfer of SM K-factors; computing NLO corrections specifically for κ_t = -1 would settle whether the enhancement factor is ~10 or ~4.","A testable extension would be to use the shape differences (harder pT(H), pT(t) tails, forward-jet η distribution) as discriminating observables independent of the rate normalization, since these arise from the interference sign change itself.","If the LO+MLM chain is validated at 14 TeV and HL-LHC luminosities, the same K-factor prescription could be applied to other BSM scenarios (e.g., CP-violating phases in the Yukawa sector) to forecast signal sensitivities."],"forward_implications":["If the LO+MLM chain with K-factors is validated, tH cross-section and shape predictions for Run 3 and HL-LHC can be produced without full NLO event generation, accelerating searches and BDT-based analyses.","The ITC scenario predicts a rate enhancement of roughly a factor of 4-5 at LO+MLM (and up to ~10 at NLO per the quoted ATLAS value) and harder pT spectra, giving distinctive signatures for H→bb and H→WW* channels.","The sign of the top Yukawa coupling becomes directly accessible via tH rate and shape measurements; HL-LHC statistics (3000-4000 fb-1) should determine κ_t to 5-10%, potentially resolving the sign.","The 4% agreement between the scaled SM prediction and the NLO reference suggests the simulation chain captures the dominant higher-order effects, supporting its use in future BSM interpretations."],"fun_headline_variants":["Hybrid flavor scheme sim reproduces SM tH; inverted coupling boosts rate","K-factor corrected LO matches ATLAS tH; flipped sign constructive","Top Yukawa probe: sign flip turns destructive to constructive in tH","Modeling tH with hybrid scheme: 4.8x rate for κ_t=-1","Inverted top-Higgs coupling enhances tH production, matching ATLAS"],"cache_read_input_tokens":2304,"weakest_assumption_plain":"The load-bearing premise is that the K-factors calibrated to the Standard Model (1.5 for tHq and 0.7 for tWH) also correct the inverted-coupling scenario, so that multiplying the ITC LO+MLM cross sections by these same factors yields a reliable NLO-equivalent prediction; if NLO corrections depend on the sign of the Yukawa coupling, the claimed 380 fb comparison with the ~890 fb ATLAS-quoted NLO value—and therefore the 'quantitative support' for the excess—collapses.","fun_headline_variants_meta":{"raw":{"variants":["Hybrid flavor scheme sim reproduces SM tH; inverted coupling boosts rate","K-factor corrected LO matches ATLAS tH; flipped sign constructive","Top Yukawa probe: sign flip turns destructive to constructive in tH","Modeling tH with hybrid scheme: 4.8x rate for κ_t=-1","Inverted top-Higgs coupling enhances tH production, matching ATLAS"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000339,"raw_usage":{"total_tokens":1732,"prompt_tokens":794,"completion_tokens":938,"prompt_tokens_details":{"cached_tokens":256},"prompt_cache_hit_tokens":256,"prompt_cache_miss_tokens":538,"completion_tokens_details":{"reasoning_tokens":836}},"tokens_in":538,"tokens_out":938,"duration_ms":9321,"temperature":1.0,"reasoning_tokens":836,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-02T19:09:05.125888+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Compute the full NLO QCD cross section for tHq and tWH production with κ_t = -1 using the same 4FS/5FS setups and cuts as in Refs. [12,15] of the paper. If the result is close to 890 fb rather than to the paper's scaled 380 fb, the assumption that SM K-factors transfer to ITC is falsified. Alternatively, an HL-LHC measurement of the tH rate consistent with the SM would rule out the ITC explanation.","supporting_citations":[],"review_version":1}