{"id":"54ee035f-dbb8-4fb4-a6c2-786b9c3928a2","arxiv_id":"2607.07811","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.5,"correctness_risk":"medium","formal_verification":"none","parameter_count":3,"one_line_summary":"Collision-induced QED radiation produces O(1) corrections to DIS cross sections but only few-percent shifts in longitudinal electron spin asymmetries, making asymmetries more robust for SMEFT constraints at SoLID and EIC.","lead":"QED radiation from charged particles can change deep-inelastic scattering cross sections by order-one amounts, but shifts electron spin asymmetries by only a few percent. This makes asymmetries far more reliable for constraining new physics at SoLID and the Electron-Ion Collider.","discovery_kind":"new_application","skeptic_critique":{"model":"grok-4.5","headline":"Polarized-LDF equality is the softest link, but the paper already flags it and the qualitative robustness claim is not overturned by it.","rationale":"The Reader correctly isolates the polarized-LDF equality as the weakest assumption that directly underwrites the strongest claim. The paper itself is transparent about the approximation and presents the result as a first analysis, so the concern does not rise to a reason for rejection. It does, however, keep the verdict at CONDITIONAL rather than ACCEPT, because the few-percent robustness of Ae is precisely the scale at which the uncontrolled non-perturbative difference could matter. No other internal inconsistency or missing ingredient (tree-level hard scattering, limited LDF parameterizations, absence of public code) is more load-bearing for the central qualitative conclusion. The concrete test above would settle whether the assumption actually compromises the advertised robustness at the level of the published contours.","tokens_in":9923,"tokens_out":506,"duration_ms":6264,"concrete_test":"Replace the equality by a one-parameter family Δfe/e = (1−ε)fe/e with ε = ±0.05 (and, if available, a realistic non-perturbative model of the polarized LDF) and recompute the bottom panels of Figs. 4 and 6. If the 95 % CL contours for (Cℓd,Ced) shift by more than the separation already shown between the NR and LF1 curves, the quantitative robustness claim needs a caveat; otherwise the assumption is safe at the precision of the present study.","verdict_should_be":"CONDITIONAL","load_bearing_attack":"The central claim that Ae is robust at the few-percent level rests on setting Δfe/e(ξ,μ) ≃ fe/e(ξ,μ) (text after Eq. (6)). The authors note that both distributions are non-perturbative and that equality is only expected at LO QED; they treat any difference as “negligible in this first analysis.” Because δA itself is only a few percent (Figs. 2–3 bottom), a non-perturbative polarization asymmetry of comparable size would move the extracted SMEFT contours by an amount comparable to the QED-induced shift the paper is advertising. The assumption is therefore load-bearing for the quantitative claim that asymmetries are “significantly more robust,” even though the qualitative hierarchy (δσ ≫ δA) is unlikely to reverse.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.5","summary":"The paper studies the impact of collision-induced QED radiation on SMEFT constraints extracted from neutral-current DIS at SoLID and the EIC. Using the joint QCD+QED factorization formula (Eq. 2) with lepton distribution and fragmentation functions, the authors compute unpolarized cross sections and longitudinal electron spin asymmetries both with and without QED radiation. They quantify the relative shifts δσ and δA (Eq. 7) and show that cross sections receive order-one corrections while asymmetries shift only at the few-percent level. Pseudo-data χ² analyses for pairs of dimension-6 four-fermion Wilson coefficients (exemplified by Cℓd, Ced) then demonstrate that SMEFT contours extracted from cross sections can be substantially biased if QED radiation is omitted, whereas contours from Ae remain comparatively stable. Three LDF/LFF parameterizations (LF1–LF3) are used to assess sensitivity.","tokens_in":10106,"tokens_out":1191,"duration_ms":12463,"significance":"If the hierarchy δσ ≫ δA holds under more complete treatments of polarized lepton distributions, the result supplies a concrete, actionable recommendation for future SoLID and EIC SMEFT programs: prefer longitudinal electron asymmetries over unpolarized cross sections when QED radiation is incompletely controlled. The work is the first application of the joint QCD+QED factorization framework to SMEFT analyses, provides transparent benchmark projections at realistic luminosities, and cleanly separates the effects of radiation from the extraction of Wilson coefficients. The numerical results (Figs. 2–6) are reproducible once the LDF parameterizations are fixed and therefore constitute a useful reference for subsequent global fits.","major_comments":[{"comment":"After Eq. (6) the polarized LDF is set equal to the unpolarized one, Δfe/e(ξ,μ) ≃ fe/e(ξ,μ), on the grounds that f−e/e ≈ 0 at LO QED and that non-perturbative differences are “negligible in this first analysis.” Because the reported δA is itself only a few percent (Figs. 2–3, bottom), a non-perturbative polarization asymmetry of comparable size would shift the Ae-based SMEFT contours by an amount comparable to the QED-induced bias the paper advertises. The equality is therefore load-bearing for the quantitative claim that asymmetries are “significantly more robust.” A short sensitivity study that varies Δfe/e/fe/e by a few percent (or an explicit statement that the robustness claim is only qualitative until polarized LDFs are measured) is needed before the central conclusion can be regarded as fully supported.","section":null},{"comment":"The hard function is restricted to the process-independent leading channel i = e, j = e (text after Eq. (3)), so that only the electron LDF and LFF enter. While this is a legitimate first step, the joint factorization formula (Eq. 2) also admits radiation off charged quarks and lepton-flavor-changing channels. In the kinematic regions where δσ becomes O(1) (moderate-to-large xB, lower Q2), these additional contributions could alter both the absolute size of the shifts and the relative stability of Ae. A quantitative estimate of their size, or a clear statement that they are deferred to future work, is required to bound the systematic uncertainty on the reported contours.","section":null}],"minor_comments":[{"comment":"Fig. 1 caption and surrounding text refer to “LDF parameterizations” while the functional form is taken from Ref. [45]; a brief explicit statement of the three parameter sets (or a pointer to a table) would improve reproducibility.","section":null},{"comment":"The definition of the hard function Ḥia\to jX = 2ŝ dσ̂ appears both in the text after Eq. (2) and again in Eq. (3); a single consistent notation would avoid confusion.","section":null},{"comment":"In the SoLID projections the luminosity is given as 106 fb−1; a short remark on how this number relates to the expected SoLID running plan would help experimental readers.","section":null},{"comment":"The phrase “quasielastic tails” in the Introduction is left undefined; a parenthetical clarification or reference would aid non-specialists.","section":null},{"comment":"Table I lists seven operators but the text states that all 21 pairs were analyzed; a sentence confirming that the (Cℓd, Ced) results are representative (or a supplementary figure for one additional pair) would strengthen the claim.","section":null}],"recommendation":"minor_revision","confidential_remarks":"The manuscript is a solid first application of the joint factorization framework to SMEFT. The polarized-LDF assumption is the only genuinely load-bearing soft spot; once the authors either quantify it or clearly flag the claim as qualitative, the paper is suitable for publication. Scope and novelty are appropriate for a letter-length hep-ph journal."},"author_rebuttal":null,"desk_editor":{"model":"grok-4.5","letter":"The new piece is the first quantitative map of how collision-induced QED radiation moves SMEFT Wilson-coefficient contours extracted from DIS at SoLID and EIC. They take the joint factorization they already published, keep the hard scattering at tree level, and show that unpolarized cross sections pick up O(1) corrections while the longitudinal electron asymmetry Ae stays at the few-percent level. That difference is then propagated into 95 % CL contours for pairs such as (Cℓd, Ced). The practical recommendation—prefer asymmetries for SMEFT work—is clear and useful for the two facilities that will actually take the data.\n\nWhat they do well is keep the calculation transparent. Three LDF/LFF shapes (LF1–LF3) are varied as a sensitivity study, the pseudo-data pipeline (luminosity, 1 % systematics, beam polarization) is standard, and the figures make the hierarchy δσ ≫ δA obvious. The factorization formula itself is the usual convolution once you accept the earlier papers; nothing is being reinvented here.\n\nThe softest spot is exactly the one the stress-test flags: they set Δfe/e ≃ fe/e because f− is expected to vanish at LO QED and non-perturbative differences are “negligible in this first analysis.” Since δA itself is only a few percent, a comparable polarization asymmetry would matter for the quantitative claim of “significantly more robust.” They already say so in the text, so it is not hidden. It does not reverse the qualitative ordering, and the cross-section contours still move a lot when QED is omitted. Other limitations—tree-level hard functions, no public LDF tables—are real but secondary for a letter of this scope.\n\nThis is for people who will actually fit SMEFT coefficients to SoLID or EIC data, or who need a clean illustration of why asymmetries are safer once QED radiation is treated on the same footing as QCD. The math and citation pattern look solid; the result is new enough and clean enough that a serious editor should send it to referees. I would cite the figures when I next discuss QED systematics in DIS SMEFT analyses.","headline":"First SMEFT application of joint QCD+QED factorization shows O(1) cross-section shifts vs few-percent asymmetry shifts at SoLID/EIC; the polarized-LDF equality is flagged and does not reverse the hierarchy.","tokens_in":10744,"tokens_out":547,"would_cite":true,"duration_ms":12840,"reading_group":"yes","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"grok-4.5","headline":"Collision-induced QED radiation shifts DIS cross sections by order one but changes electron spin asymmetries by only a few percent, so asymmetries give more stable SMEFT constraints.","keywords":["SMEFT","deep inelastic scattering","QED radiation","lepton distribution functions","electron spin asymmetry","SoLID","Electron-Ion Collider"],"falsifier":"A direct measurement of the polarized electron distribution function that shows a several-percent difference from the unpolarized distribution, or a high-statistics comparison of measured Ae with the joint-factorization prediction that finds a residual QED shift larger than a few percent.","tokens_in":10762,"feed_emoji":"⚡","tokens_out":661,"duration_ms":6322,"temperature":0.7,"pith_summary":"This paper asks how much collision-induced QED radiation from charged leptons and quarks spoils the extraction of new-physics parameters from deep-inelastic scattering. Using a joint QCD+QED factorization that treats lepton distribution and fragmentation functions on the same footing as ordinary parton distributions, the authors show that unpolarized cross sections can receive order-one corrections, especially at moderate-to-large Bjorken-x and lower Q^{2}. By contrast, the parity-violating longitudinal electron spin asymmetry Ae is shifted by only a few percent across the same kinematic range. Because of that relative stability, SMEFT Wilson-coefficient contours derived from Ae remain far more consistent when QED radiation is included or varied than contours derived from the cross section alone. Benchmark projections for the proposed SoLID experiment and the Electron-Ion Collider illustrate the practical size of the bias and the luminosity needed to distinguish different lepton-distribution parameterizations.","feed_headline":"QED radiation hits DIS cross sections hard, asymmetries far less","feed_subtitle":"Few-percent shifts in electron spin asymmetries keep SMEFT fits stable at SoLID and the EIC","key_machinery":"Joint QCD+QED factorization formula (Eq. 2) that convolves lepton distribution functions, lepton fragmentation functions and ordinary PDFs with a hard partonic cross section containing both Standard-Model and linear SMEFT contributions; the relative shifts δσ and δA defined in Eq. (7) quantify the size of the QED effect.","core_discovery":"When collision-induced QED radiation is included through lepton distribution and fragmentation functions, unpolarized DIS cross sections receive order-one relative corrections δσ while the longitudinal electron spin asymmetry Ae receives only few-percent corrections δA. Consequently, 95 % confidence-level contours on pairs of SMEFT four-fermion coefficients extracted from Ae are far more stable against the inclusion or variation of QED radiation than the corresponding contours extracted from the cross section.","pith_inferences":[],"forward_implications":[],"fun_headline_variants":["QED radiation shifts DIS cross sections order-one, Ae few percent","Spin asymmetries stay robust for SMEFT under QED radiation in DIS","Order-one QED effects hit unpolarized DIS rates, Ae barely shifts","Ae contours for SMEFT hold steady as QED radiation varies in DIS","QED radiation corrects DIS cross sections strongly, asymmetries mildly"],"cache_read_input_tokens":7936,"weakest_assumption_plain":"The polarized lepton distribution is taken equal to the unpolarized one, so that any non-perturbative difference between them is assumed negligible at the few-percent level that would otherwise affect the claimed robustness of the asymmetry.","fun_headline_variants_meta":{"raw":{"variants":["QED radiation shifts DIS cross sections order-one, Ae few percent","Spin asymmetries stay robust for SMEFT under QED radiation in DIS","Order-one QED effects hit unpolarized DIS rates, Ae barely shifts","Ae contours for SMEFT hold steady as QED radiation varies in DIS","QED radiation corrects DIS cross sections strongly, asymmetries mildly"]},"model":"grok-4.5","effort":"low","cost_usd":0.004368,"raw_usage":{"total_tokens":1264,"prompt_tokens":708,"num_sources_used":0,"completion_tokens":82,"cost_in_usd_ticks":43680000,"prompt_tokens_details":{"text_tokens":708,"audio_tokens":0,"image_tokens":0,"cached_tokens":256},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":474,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":708,"tokens_out":82,"duration_ms":6449,"temperature":1.0,"reasoning_tokens":474,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-07-10T17:35:00.110580+00:00","model_set":{"reader":"grok-4.5"},"falsifier":"A direct measurement of the polarized electron distribution function that shows a several-percent difference from the unpolarized distribution, or a high-statistics comparison of measured Ae with the joint-factorization prediction that finds a residual QED shift larger than a few percent.","supporting_citations":[],"review_version":1}