{"id":"ecffc6bc-1843-49a3-92dd-2477dc71ab53","arxiv_id":"2502.03168","paper_version":1,"verdict":"REJECT","confidence":"MODERATE","novelty_score":4.0,"correctness_risk":"high","formal_verification":"none","parameter_count":10,"one_line_summary":"A minijet eikonal fit to CERN forward data cannot describe the 13 TeV rho parameter and attributes the mismatch to an odd semihard component that is not yet included in the model.","lead":"This paper fits a QCD-inspired model to proton-proton and proton-antiproton scattering data from TOTEM and ATLAS/ALFA. It argues that both datasets indicate a need for an odd, crossing-antisymmetric semihard component at high energies, though the component itself is not yet implemented in the fits.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The paper's key inference is untested: no odd semihard amplitude is ever fitted, so the residual at 13 TeV rho shows only that this particular even-only model fails, not that an odd semihard component is necessary.","rationale":"I read this as a short proceedings fit report whose tables and χ2 values are not in question. The problem is the inference from a residual. The paper says the 13 TeV ρ data are not well described and immediately concludes that an odd semihard amplitude persisting at high energies is necessary. That is a causal attribution made without constructing or fitting the proposed term. The manuscript even states the extension is forthcoming, which is an explicit limitation. The fixed soft parameters are plausible but not uniquely constrained; the text provides no argument that freeing them would not resolve the tension, so the necessity claim is not robust. The reader's weakest assumption correctly identifies this gap; my stress-test agrees. Given the central claim is the paper's stated purpose and is not supported by any computation in the paper, the rejection verdict should stand. If the authors implement the odd semihard term and show a significant improvement over the even-only model with free soft parameters, the claim could be revisited.","tokens_in":4333,"tokens_out":11321,"duration_ms":107636,"concrete_test":"Refit Ensembles A and T with the same even-only semihard model (Eqs. 2–10), but with γ and μ−_soft treated as free parameters and pTmin allowed to vary over 1.0–1.3 GeV. If for either ensemble the 13 TeV ρ point can be brought within 1σ of the data without increasing the global χ2/ν relative to Table I, the residual is not evidence for the necessity of an odd semihard component. A complementary refit adding an explicit odd semihard term, e.g. χ−_SH(s,b) = ½ N− σ̃(s) e^{−iπ/4} W_SH(b; ν−_SH), should also be run; if N− is consistent with zero or the term does not improve the 13 TeV ρ fit, the proposed mechanism is directly falsified.","verdict_should_be":"REJECT","load_bearing_attack":"The central claim is that both TOTEM and ATLAS/ALFA ensembles 'necessitate' a crossing-odd semihard amplitude at high energies. The fitted model contains no such term: Eq. (7) uses only the even semihard eikonal χ+_SH, and the only odd term is the soft Regge term of Eq. (9), with γ=0.7 and μ−_soft=0.5 GeV fixed. The evidence is that the 13 TeV ρ points are 'not well-described' while overall χ2/ν is 1.18/1.10. A residual in one parameterization is not a necessity proof: freeing γ and μ−_soft, varying pTmin or the PDF set, or adjusting the known TOTEM/ATLAS normalization offsets could absorb the same residual within an even-only model. The final paragraph of Sec. III explicitly defers the odd-semihard calculation ('As an extension...'); no version of the proposed amplitude is compared with alternatives. With ν≈160, one bad ρ point contributes little to χ2/ν, so the reported global fit quality does not establish the significance of the residual. The conclusion therefore outruns the calculation; the fit tables may be useful, but the headline inference is unsupported.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"This short proceedings paper presents a QCD-based eikonal minijet model for pp and \\bar{p}p forward scattering. The even semihard eikonal is computed with NLO partonic cross sections (Eqs. 2–7), and the soft eikonal is parameterized with even and odd terms (Eqs. 8–9). The model is fitted to two ensembles of high-energy forward data, one including TOTEM and one including ATLAS/ALFA; the fits give \\chi^2/\\nu = 1.18 and 1.10 (Table I). The authors report that the \\rho data at \\sqrt{s} = 13 TeV are not well described and use this residual to conclude that an odd semihard component is necessary at high energies, although such a component is not implemented in the fits.","tokens_in":4767,"tokens_out":5033,"duration_ms":43952,"significance":"If the claimed necessity of a high-energy odd semihard amplitude were demonstrated, the result would be noteworthy: it would indicate that the standard even-semihard minijet picture is incomplete and would motivate a new class of models for the forward amplitude. The paper's positive features are the explicit NLO treatment of the jet cross section and the separate fits to the TOTEM and ATLAS/ALFA data, which document the known normalization tension. However, the central claim is not tested: no model containing an odd semihard eikonal is fitted, no alternative explanation (fixed soft parameters, PDF choice, normalization offsets) is quantified, and no statistical significance of the 13 TeV \\rho residual is reported. The conclusion therefore outruns the presented analysis.","major_comments":[{"comment":"The central claim that an odd semihard component is necessary is not supported by any fit containing such a component. The model fitted in Table I uses \\chi^-_{SH} = 0 (Section II), so the residual in \\rho at \\sqrt{s} = 13 TeV can only show that the even-only model fails for that point. The paper does not report \\Delta\\chi^2, pulls, or an alternative fit with a nonzero odd semihard eikonal; the final paragraph of Section III explicitly defers this calculation to a future study. Without such a comparison, the residual is not evidence that an odd component is required.","section":"Section III; Table I"},{"comment":"The claim that dispersion relations 'necessitate' an odd semihard component is not quantitative. Dispersion relations connect the real and imaginary parts of the amplitude but do not determine the parity decomposition of the semihard eikonal. The authors do not test whether the same \\rho residual could be absorbed by freeing \\gamma and \\mu^-_{soft} (which are fixed to 0.7 and 0.5 GeV), by varying pTmin, by changing the PDF set, or by applying the known TOTEM/ATLAS normalization offsets. Any of these alternatives could absorb the residual within an even-only model.","section":"Section III, paragraph 2"},{"comment":"The reported goodness of fit does not establish the significance of the 13 TeV \\rho discrepancy. With \\nu = 168 (TOTEM) and 158 (ATLAS), a single deviant point contributes little to \\chi^2/\\nu = 1.18 or 1.10. The authors should report the per-point \\chi^2 of the 13 TeV \\rho measurements, the fitted \\rho values, and the change in \\chi^2 when these points are removed. Without this information, the statement that the data are 'not well-described' cannot be weighed.","section":"Table I; Section III"}],"minor_comments":[{"comment":"There are typographical errors: 'ATLAS/ALF A' should be 'ATLAS/ALFA' in the abstract and in Section I.","section":"Abstract and Section I"},{"comment":"Equation (6) contains a formatting error in the PDF product: the second factor should read f_{j/B}(x2, |\\hat t|), not f_{j/B}(x2, |\\hat t)|).","section":"Equation (6)"},{"comment":"The PDF set (CT18) and the value of \\alpha_s used are not specified; these details are needed for reproducibility of the NLO jet cross section calculation.","section":"Section II"},{"comment":"The construction of the \\chi^2 function is not described. It is unclear whether normalization uncertainties of TOTEM and ATLAS/ALFA were treated as free shifts or as fixed offsets in the fits.","section":"Section III"},{"comment":"The figures show the fitted curves and data, but the text does not discuss the residuals. A plot of the \\rho residuals at LHC energies would directly illustrate the claimed problem.","section":"Figures 1 and 2"}],"recommendation":"reject","confidential_remarks":"This is a proceedings contribution whose headline conclusion is not derived or tested in the paper. The necessary new ingredient (a fitted odd semihard eikonal) is large enough that adding it would constitute a new study. I would not expect the journal to invest in a major revision of a short proceedings write-up for this; the paper might be more appropriately published as a brief model description without the 'necessity' claim."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Colleague,\n\nTwo things to know. First, this is a short proceedings paper that re-fits the authors' eikonal minijet model to forward pp and pbarp data using CT18 PDFs, splitting TOTEM and ATLAS/ALFA into two ensembles. The fits are respectable (chi2/nu 1.18 and 1.10). Second, the advertised conclusion—that both datasets require a crossing-odd semihard component at high energies—is not derived anywhere in the paper. No model containing an odd semihard term is fitted, no delta-chi2 is reported, and the only evidence is that the 13 TeV rho point is not well described by the even-only model.\n\nWhat is new and useful: the use of CT18 PDFs in this framework, the explicit separation into TOTEM and ATLAS ensembles, and the parameter tables. The model itself goes back to earlier work by the group, but the update is clean and the fit quality is acceptable. The authors also state plainly which parameters are fixed (gamma=0.7, mu-_soft=0.5 GeV) and which are fitted, which makes the analysis reproducible in principle.\n\nThe soft spot is the inference, not the computation. The paper says 'regardless of which normalization ... is accurate, a satisfactory description of rho necessitates the inclusion of an odd component.' That is not supported by the evidence. The residual at 13 TeV shows only that this particular even-only model with those fixed parameters misses one point. It doesn't rule out freeing gamma and mu-_soft, adjusting pTmin or the PDF set, or adding a simple soft-odderon term, any of which could absorb the same residual. Worth noting: with nu around 160, a single bad rho point contributes little to chi2/nu, so the good global chi2 doesn't strengthen the claim. The paper even ends by deferring the odd-semihard calculation to 'an extension of this study,' which confirms that the headline is a prediction of future work, not a result of this one.\n\nSo who is this for? A specialist in high-energy forward scattering might want the fit tables and the ensemble comparison. But anyone citing this for the odd semihard component would be over-reading. The authors are capable and the framework is coherent; they just haven't done the calculation they claim points to necessity.\n\nI would treat this as a solid conference report whose conclusion overstates its evidence. If the venue wants the necessity claim, a serious referee should send it back for either the full implementation or a heavily toned-down conclusion. I wouldn't desk reject, though the paper needs revision to earn the central claim.\n\nRead it as a cautionary example of residual-driven speculation, not as evidence for an odd semihard amplitude.","headline":"Solid fits, but the advertised odd semihard component is never actually fitted — the conclusion outruns the calculation.","tokens_in":5257,"tokens_out":2675,"would_cite":false,"duration_ms":24320,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"A QCD minijet eikonal model finds that describing the measured ratio of real to imaginary forward amplitude at 13 TeV requires an odd semihard component, independent of the TOTEM/ATLAS normalization choice.","keywords":["minijet model","semihard interactions","total cross section","rho parameter","eikonal model","next-to-leading-order QCD","TOTEM","ATLAS/ALFA"],"falsifier":"A global fit that keeps the semihard eikonal purely even but lets $\\gamma$ and $\\mu^-_{\\rm soft}$ float, or that changes the soft dipole form factor, would falsify the central claim if it then reproduces the 13 TeV $\\rho$ values from both TOTEM and ATLAS/ALFA within uncertainties.","tokens_in":4054,"feed_emoji":"⚛️","tokens_out":14458,"duration_ms":108931,"temperature":0.7,"pith_summary":"This paper is about what actually controls the forward proton-antiproton amplitude at LHC energies. The authors run a QCD eikonal minijet model—where the growth of the total cross section comes from semihard gluon-dominated jet production—against the world's $pp$ and $\\bar{p}p$ data at $\\sqrt{s} \\ge 10$ GeV, fitting the TOTEM and ATLAS/ALFA normalizations separately. Both fits reproduce the total cross section well, but both miss the measured value of $\\rho$ at 13 TeV, the ratio of the real to imaginary parts of the forward amplitude. Because dispersion relations tie $\\rho$ tightly to the energy growth of the total cross section, the authors read this residual as evidence that the semihard amplitude itself must carry an odd (particle-antiparticle antisymmetric) component that does not vanish at high energies. If they are right, the standard even-only semihard picture is incomplete, and the real part of the high-energy amplitude is shaped by semihard dynamics, not just soft physics.","feed_headline":"Minijet fits at LHC demand an odd high-energy amplitude","feed_subtitle":"Both TOTEM and ATLAS/ALFA fits miss the rho ratio unless an odd semihard term survives at high energy.","key_machinery":"The load-bearing object is the semihard eikonal pair. The even piece is $\\chi^+_{\\rm SH}(s,b) = \\frac{N}{2}\\tilde{\\sigma}(s)\\,W_{\\rm SH}(b;\\nu_{\\rm SH})$, with $\\tilde{\\sigma}(s)$ the NLO QCD jet cross section (CT18 PDFs, $p_{T\\min}=1.1$ GeV), $N$ a phenomenological factor absorbing the K-factor and cutoff uncertainty, and $W_{\\rm SH}(b) = \\frac{\\nu_{\\rm SH}^2}{96\\pi}(\\nu_{\\rm SH}b)^3 K_3(\\nu_{\\rm SH}b)$ a dipole overlap density. The model sets the odd semihard eikonal to zero, leaving the soft eikonal as the only source of crossing-odd behavior. The forward observables $\\sigma_{\\rm tot}(s)$ and $\\rho(s)$ are computed from the full eikonal via standard integrals, and dispersion relations tie $\\rho$ to the energy growth of $\\sigma_{\\rm tot}$; that tie is what converts the 13 TeV $\\rho$ mismatch into evidence for an omitted odd semihard amplitude.","core_discovery":"The central claim is that a purely even semihard amplitude cannot describe the forward $pp$ amplitude at 13 TeV. In the model, the eikonal is the sum of a soft piece (with an odd term) and a semihard piece driven by the NLO QCD cross section for jet production, and the forward observables $\\sigma_{\\rm tot}(s)$ and $\\rho(s)$ follow from the eikonal through standard integrals. Global fits using CT18 PDFs and $p_{T\\min}=1.1$ GeV give $\\chi^2/\\nu \\simeq 1.18$ (TOTEM-based) and $1.10$ (ATLAS-based), so the total cross section over a wide energy range is described; the failure is concentrated in the 13 TeV $\\rho$ point. The authors conclude that, independent of which collaboration's normalization is correct, a satisfactory description of $\\rho$ requires adding an odd component to the semihard amplitude that persists asymptotically. They explicitly leave the implementation of that odd semihard term to a future study.","pith_inferences":["A testable extension: if the odd semihard term persists asymptotically, it predicts a non-vanishing and possibly growing difference between proton-proton and proton-antiproton total cross sections at LHC energies.","The paper's inference rests on the fixed soft parameters $\\gamma = 0.7$ and $\\mu^-_{\\rm soft} = 0.5$ GeV; a fit that lets these parameters float while keeping the semihard sector even would show whether the 13 TeV $\\rho$ residual can be absorbed without new odd physics.","The proposed odd term would most naturally be generated by C-odd (three-gluon) exchange in the semihard regime, giving the model a concrete partonic interpretation to test.","A targeted check is the energy slope of $\\rho$: a persistent odd semihard amplitude should leave a distinctive imprint in $\\rho(s)$ between 7 and 14 TeV that differs from the even-only prediction."],"forward_implications":["A purely even semihard amplitude cannot describe the forward proton amplitude at 13 TeV; an odd semihard term that persists at high energies must be added.","The requirement holds for both TOTEM and ATLAS/ALFA normalizations, so it does not depend on which collaboration's absolute scale is correct.","The extension should fix the 13 TeV rho point while leaving the already good description of the total cross section largely unchanged.","The paper explicitly plans to implement the odd semihard component and to test the sensitivity of the results to the choice of parton distribution functions."],"supporting_citations":[{"why":"It supplies the eikonal minijet formalism with additive soft and semihard eikonals used to derive the model's predictions.","marker":"[3, 4, 10, 11]"},{"why":"It provides the CT18 NLO parton distribution functions used in the semihard jet cross section.","marker":"[22]"},{"why":"It defines Ensemble A through the ATLAS/ALFA measurements used for the high-energy fits.","marker":"[13–15]"},{"why":"It defines Ensemble T through the TOTEM measurements used for the LHC-energy fits.","marker":"[16–21]"},{"why":"It provides the low-energy pp and proton-antiproton forward data used as global constraints in both fits.","marker":"[12]"}],"fun_headline_variants":["Odd semihard term needed to fix rho at 13 TeV","LHC data hint at odd amplitude in semihard QCD","Minijet model requires odd component for forward scattering","Semihard glue needs odd piece for high-energy rho","Forward data force odd semihard amplitude at LHC"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The paper's conclusion assumes that the 13 TeV $\\rho$ mismatch reflects missing physics in the semihard amplitude rather than the fixed values of the soft-eikonal parameters $\\gamma$ and $\\mu^-_{\\rm soft}$ or other modeling choices.","fun_headline_variants_meta":{"raw":{"variants":["Odd semihard term needed to fix rho at 13 TeV","LHC data hint at odd amplitude in semihard QCD","Minijet model requires odd component for forward scattering","Semihard glue needs odd piece for high-energy rho","Forward data force odd semihard amplitude at LHC"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000166,"raw_usage":{"total_tokens":1223,"prompt_tokens":885,"completion_tokens":338,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":501,"completion_tokens_details":{"reasoning_tokens":251}},"tokens_in":501,"tokens_out":338,"duration_ms":3433,"temperature":1.0,"reasoning_tokens":251,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-09T05:39:28.133411+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"A global fit that keeps the semihard eikonal purely even but lets $\\gamma$ and $\\mu^-_{\\rm soft}$ float, or that changes the soft dipole form factor, would falsify the central claim if it then reproduces the 13 TeV $\\rho$ values from both TOTEM and ATLAS/ALFA within uncertainties.","supporting_citations":[{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"It provides the CT18 NLO parton distribution functions used in the semihard jet cross section."}],"review_version":1}