{"id":"4716aff4-dad3-4df3-9480-565bbcbc2d65","arxiv_id":"2501.08984","paper_version":2,"verdict":"CONDITIONAL","confidence":"HIGH","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":0,"one_line_summary":"A simulation study proposes COM variables for CC1π1p neutrino events that isolate final-state interactions from nuclear initial-state and flux effects.","lead":"This paper proposes two new kinematic variables, the centre-of-momentum angle and total energy, for neutrino interactions that produce one pion and one proton. In Monte Carlo simulations, the angle appears largely insensitive to the nuclear initial state and to neutrino flux differences, and sensitive to final-state interactions, which could help models of neutrino-nucleus scattering.","discovery_kind":"new_method","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The claim that θCOM deviates from θπΔ only through FSI rests on θπΔ being independent of IS and Eν, yet Fig. 2c (FSI-off C vs H, χ²/NDF=32/8) and Fig. 9b (H Δ++-only at 5 GeV, χ²/NDF=95/8) show such dependence; these residuals are unexplained and load-bearing.","rationale":"The paper is honest and well-scoped: it uses truth-level MC only, acknowledges that reconstruction was not studied, and flags the 5 GeV and FSI-off-C/H residuals as open questions. Those are real strengths. But the central physical argument is not the reconstruction gap; it is the premise that θπΔ itself is a universal rest-frame property. The paper's own simulations provide a sharp falsification of that premise. Since θCOM equals θπΔ whenever FSI is absent, the observed FSI-off target dependence and mono-energetic Eν dependence are direct evidence that generator θπΔ depends on IS and production kinematics. The author's suggested explanation for Fig. 9b—'influence of Δ++ kinematics on their decay'—is in tension with the Sec. II statement that θπΔ is independent of the resonance's momentum. The 5 GeV bin may be a small fraction of real fluxes, and the FSI signal (χ²=64/8) is larger than the IS residual (χ²=32/8), so the paper's weaker claims of 'minimal dependence' and 'sensitivity to FSI' may survive. But the strong claim that θCOM isolates FSI, and the direct cross-experiment comparison claim, require either controlling these residuals or understanding them. The proposed check—comparing true θπΔ distributions—settles whether the premise is wrong in GENIE or whether the residual comes from selection/tagging. Because the reader's CONDITIONAL verdict already captures this as the weakest assumption, I do not adjust the verdict.","tokens_in":16338,"tokens_out":7536,"duration_ms":79818,"concrete_test":"Using the same G24-0 GENIE configuration, generate Δ++-only ν-H and FSI-off ν-C samples at Eν = 0.5, 1.0, 2.0, 5.0 GeV and compare the true rest-frame θπΔ distributions directly, before any boost to the lab frame. If θπΔ varies with Eν or with target/IS model, the Sec. II premise fails and θCOM cannot be claimed to deviate from θπΔ only through FSI. If θπΔ is flat across these conditions, the residual θCOM differences must instead come from the event selection or from the Δ++-only tagging, and the explanation of Fig. 9b needs revision.","verdict_should_be":"UNCHANGED","load_bearing_attack":"In Sec. II the paper asserts that θπΔ is 'independent of the resonance's momentum, neutrino energy, and IS,' and therefore 'θCOM deviates from θπΔ only due to FSI.' For any event without FSI, psum = pΔ, so the COM frame is exactly the Δ rest frame and θCOM = θπΔ event-by-event. Consequently, any IS- or Eν-dependence in FSI-off θCOM distributions is, by construction, a dependence of the generator's θπΔ on those quantities. The paper's own Figs. 2c and 9b violate this premise. With FSI disabled, carbon Δ++-only θCOM differs from hydrogen at χ²/NDF = 32/8 (8 dof; p ≈ 1e-4), so the nuclear initial state changes θπΔ in GENIE. On hydrogen with Δ++-only events, Eν = 5.0 GeV gives χ²/NDF = 95/8 relative to Eν = 0.5 GeV. The author attributes this to 'the influence of Δ++ kinematics on their decay' (Sec. III), which directly contradicts the stated independence. Since a flux with any substantial high-Eν tail will populate such events, the claimed 'practical' flux independence and the use of θCOM to isolate FSI are not established by the shown MC. The author flags these as puzzles for future work (Secs. II, III), but they are exactly the assumptions that carry the central claim.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"This paper proposes a new pair of observables for νμ CC1π1p events: the centre-of-momentum angle θCOM and total energy ECOM, reconstructed purely from the final-state proton and pion momenta. The central idea is that in the absence of FSI the COM frame coincides with the Δ++ rest frame, so θCOM equals the resonance decay angle θπΔ; the paper asserts that θπΔ is independent of the resonance momentum, the neutrino energy, and the nuclear initial state, and therefore that deviations of θCOM from θπΔ isolate FSI. Using GENIE simulations across six tunes, the T2K and MINERvA fluxes, mono-energetic beams, and hydrogen and carbon targets, the paper reports strong FSI sensitivity (χ2/NDF = 29/8 to 746/8 for FSI model changes and for FSI on/off), modest IS sensitivity for specific IS variants, and compatibility of hydrogen-target θCOM shapes across three fluxes (χ2/NDF = 9/8 and 10/8). Several residuals — the FSI-off ν-C versus ν-H difference (32/8) and the Eν = 5 GeV hydrogen anomaly (95/8) — are identified explicitly by the author as puzzles for future work.","tokens_in":16629,"tokens_out":27902,"duration_ms":252941,"significance":"The proposal is attractive and timely: θCOM requires no neutrino-energy reconstruction, the cross-experiment hydrogen comparison in Fig. 11 is a concrete falsifiable prediction, and the MC survey is unusually broad, including a null control (Fig. 3b) and explicit acknowledgement of the anomalies that limit the claims. Credit should also go to the absence of any fitting to the θCOM distributions, so the FSI-sensitivity result is not circular; the G24-c tune of Ref. [17] is used as one independent model variant among several, which is appropriate. If the independence claims are recalibrated to the level the evidence actually supports — comparative robustness against the tested GENIE IS, RES, and flux variations, with the FSI-off residual carried as a systematic — the paper is a useful methodological contribution. The current wording in the abstract and Sec. II overstates the independence, and the paper's own FSI-off and mono-energetic tests contradict that wording at high statistical significance.","major_comments":[{"comment":"The paper's conceptual foundation is the Sec. II statement that θπΔ is independent of the resonance's momentum, neutrino energy, and IS, so that θCOM deviates from θπΔ only through FSI. This premise is directly tested by the paper's own FSI-off comparison: with FSI disabled, the four-momentum sum of the final-state proton and pion equals pΔ, so the COM frame coincides with the Δ++ rest frame and θCOM = θπΔ event-by-event. Fig. 2c then shows that the ν-C FSI-off Δ++-only distribution differs from ν-H with χ2/NDF = 32/8, which for eight degrees of freedom corresponds to p ≈ 1e-4; the accompanying text calls this 'almost statistically compatible,' which understates the discrepancy. The residual implies either that θπΔ in GENIE depends on the nuclear initial state (contradicting the premise) or that the CC1π1p selection on carbon biases the sampled decay angle through proton or pion momentum thresholds; the manuscript resolves neither, and it explicitly defers the cause to future studies. Because the FSI-isolation argument follows entirely from this premise, the author should quantify this residual as an initial-state systematic and test the threshold/selection explanation with truth-level comparisons in which identical momentum thresholds are applied to hydrogen and carbon.","section":"Sec. II; Figs. 2b-2c"},{"comment":"The claimed independence of θCOM from neutrino energy is contradicted by Fig. 9b: for a hydrogen target, with no FSI and no IS, the Δ++-only θCOM distribution at Eν = 5.0 GeV differs from that at Eν = 0.5 GeV with χ2/NDF = 95/8 (p ≪ 1e-4). The explanation offered in Sec. III — that more energetic Δ++ resonances enhance the influence of their kinematics on the decay — retracts the Sec. II claim that θπΔ is independent of the resonance's momentum and neutrino energy, and the paper defers a full explanation as 'beyond the scope of this work.' The further assertion that such neutrinos contribute only 'marginally to actual cross-section measurements' is not quantified, which is consequential because the MINERvA LE flux peaks near 3.5 GeV and has a non-negligible high-energy tail. Since the ECOM < 1330 MeV cut used elsewhere (Figs. 7d, 8b, 11) is not applied in Fig. 9, the author should show whether this cut removes the 5-GeV deviation and should give flux-weighted estimates of the effect for the T2K and MINERvA fluxes.","section":"Sec. III; Fig. 9b"},{"comment":"The paper's comparative conclusions rest on χ2/NDF values computed with statistical uncertainties only on 600,000-event MC samples, so the absolute scale of these values is arbitrary; the qualitative labels attached to them are then applied inconsistently. χ2/NDF = 32/8 is called 'almost statistically compatible' (Fig. 2c), while χ2/NDF = 29/8 is described as a 'considerable difference' (Fig. 5b); χ2/NDF = 20/8 is 'relatively compatible' (Fig. 10b) and 15/8 is 'statistically compatible' (Fig. 7d), yet the first two pairs have nearly identical p-values. A stated criterion, such as a p-value threshold or an effect-size metric, and a consistent vocabulary are needed before the robustness and sensitivity claims can be evaluated quantitatively.","section":"Figs. 2-12 (chi2/NDF reporting)"},{"comment":"The IS-robustness claim in the abstract is supported by evidence that is more limited than the wording suggests. The direct IS-model comparison in Fig. 3a gives χ2/NDF = 18/8 for θCOM, while the conceptually IS-sensitive Adler angle shows an even smaller change (12/8, Fig. 3b); the author explicitly notes that this could challenge the claimed IS insensitivity. The removal-energy stress test in Fig. 4 separates the two variables clearly at the physical 40 MeV value (6/8 for θCOM versus 109/8 for θAdt), but the clearer separations at 90 and 180 MeV are obtained at removal energies that the author describes as unphysical or far beyond realistic values. The IS conclusion should therefore be stated as robustness against the specific IS variants tested in GENIE, with the FSI-off ν-C/ν-H residual of Figs. 2b-2c carried as part of the IS systematic, rather than as the general independence asserted in Sec. II.","section":"Sec. III; Figs. 3-4"}],"minor_comments":[{"comment":"Several typographical and editorial errors remain: 'utilitiy' in Sec. II; 'hen such a sample' at the opening of Sec. V; 'ECOM < 1330 GeV' should read MeV in Sec. II; 'configuations' in the caption of Fig. 12; an unresolved 'Ref. [ ? ]' in the W-derivation sentence of Sec. III; and a cross-reference in the ECOM-cut discussion that says 'Fig. 7c' where the text appears to mean Fig. 7d.","section":"Throughout"},{"comment":"The text says the χ2/NDF values in Fig. 9a are 'on the order of 100/8,' but the listed values range from 75/8 to 1247/8; the summary should state the actual values.","section":"Sec. III; Fig. 9a"},{"comment":"The statement that 'MINERvA has already conducted a ν-H selection' cites Ref. [44], which reports a pion-less antineutrino-proton measurement; the feasibility claim for a CC1π1p hydrogen selection should be qualified so that it does not imply that the same topology was already measured on hydrogen.","section":"Sec. III; Ref. [44]"},{"comment":"The truth-level CC1π1p selection is not fully specified (proton and pion momentum thresholds, pion charge sign, acceptance); these details matter for interpreting the FSI-off comparisons in Fig. 2 and the mono-energetic comparisons in Figs. 9-10, where threshold effects could mimic IS or Eν dependence.","section":"Sec. III; Figs. 2, 9-10"},{"comment":"Fig. 11 demonstrates flux independence using a single generator (G24-0); the conclusion that θCOM distributions can be directly compared across different experiments would be strengthened by a cross-generator control on hydrogen, since the claim is ultimately about comparing data rather than simulations.","section":"Sec. III; Fig. 11"}],"recommendation":"major_revision","confidential_remarks":"This is a single-author methodology paper in the T2K/GENIE ecosystem, and the proposed variable is a reasonable candidate for a legitimate new observable; the paper fits the scope of a journal such as Physical Review D. I agree with the stress-test concern: the paper's own Figs. 2c and 9b contradict the Sec. II independence premise at high statistical significance, and the manuscript's limitation statements explicitly defer the causes to future work. I am not recommending rejection, because the underlying idea is defensible if the claims are recalibrated and the residuals are quantified; but I would ask the editor to hold the paper to the quantifications in major comments 1-3 before acceptance. The self-citation of Ref. [17], the author's own TKI tuning paper, is transparent and appropriate here."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"The one thing to know: this is not another reinterpretation of TKI or the Adler angle. The COM variables are a genuinely new construction for CC1π1p events, defined purely from the measured proton and pion momenta. The paper does a good job showing that θ_COM separates FSI models clearly (hA vs hN, χ²/NDF=64/8; tuned vs default hA, 29/8) and that it is comparatively stable under IS model changes and removal-energy variations. The author also deserves credit for using his own tuned GENIE configuration as an independent variant rather than as a forced input, and for explicitly flagging the residuals that complicate his central claim.\n\nThe soft spot, and it is load-bearing, is the assertion that θ_COM deviates from θπΔ only due to FSI. When FSI is off, p_sum = pΔ, so θ_COM equals θπΔ event-by-event. That means any IS- or Eν-dependence in the FSI-off θ_COM distributions is, by construction, a property of the generator's θπΔ. The paper's own Fig. 2c shows FSI-off carbon vs hydrogen for Δ++-only events with χ²/NDF = 32/8, and Fig. 9b shows 5 GeV hydrogen diverging from lower energies with χ²/NDF = 95/8. The author calls these puzzles for future work, but they are exactly what undermines the stated independence. The practical case for T2K may survive—the 5 GeV tail is small—but the abstract's blanket statement that θ_COM is independent of Eν and IS is too strong. A related overreach is the 'first opportunity for direct cross-comparison' claim: it rests entirely on MC, with the MicroBooNE hydrogen sample being simulated rather than measured.\n\nMissing entirely is any treatment of detector reconstruction—smearing, efficiency, or proton/pion momentum resolution. The author acknowledges this in Sec. IV, but it is a significant omission for a paper whose stated goal is to motivate a future cross-section measurement. The omission is addressable in revision.\n\nWho is this for? Neutrino cross-section experimentalists, especially those at T2K and DUNE, and GENIE model developers. They will read it with interest, even if they come away less convinced than the abstract suggests. The paper is honest, the MC tests are well designed, and the residual problems are identified rather than hidden. It deserves a serious referee, not a desk reject. My recommendation: send it out, and ask the authors to quantify the θπΔ dependence, soften the abstract, and add a reconstruction study before publication.\n\nAltogether, this is a solid first proposal of a potentially useful observable, with a central claim that needs to be scaled back to 'robust in a restricted energy and target regime' rather than 'independent of IS and Eν.'","headline":"A genuinely new hadron-only kinematic variable for CC1π1p with real FSI sensitivity, but the paper's central independence claim is contradicted by its own FSI-off residual χ² values—still worth a rigorous referee because the idea is fresh and the work is honest.","tokens_in":17201,"tokens_out":2494,"would_cite":true,"duration_ms":28973,"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":"The paper argues that a centre-of-momentum angle built from measured proton and pion momenta isolates final-state interactions in neutrino-nucleus scattering, enabling cross-experiment comparison.","keywords":["centre-of-momentum angle","final-state interactions","neutrino-nucleus scattering","single-pion production","CC1π1p events","Monte Carlo simulation","cross-experiment comparison"],"falsifier":"Generate $\\Delta^{++}$-only CC1$\\pi$1p events on hydrogen and carbon with FSI switched off using much larger statistics than the 600,000-event samples in this study; if the $\\theta_{\\rm COM}$ distributions remain incompatible at the level seen here ($\\chi^2/{\\rm NDF} = 32/8$), or if the 5 GeV hydrogen distribution keeps its $\\chi^2/{\\rm NDF} = 95/8$ deviation, the claimed independence from initial state and neutrino energy is falsified.","tokens_in":16083,"feed_emoji":"⚛️","tokens_out":13655,"duration_ms":116834,"temperature":0.7,"pith_summary":"This paper proposes a new kinematic variable, the centre-of-momentum angle $\\theta_{\\rm COM}$, built from the measured proton and pion momenta in charged-current single-pion single-proton ($\\nu_\\mu$CC1$\\pi$1p) neutrino events. The claim is that $\\theta_{\\rm COM}$ is shaped almost entirely by final-state interactions (FSI) inside the nucleus, and is nearly insensitive to the nuclear initial state, to resonance-model details, and to the neutrino energy spectrum. Using Monte Carlo simulations on carbon and hydrogen targets, the author shows that different FSI models produce incompatible $\\theta_{\\rm COM}$ distributions, while changing initial-state models, removal energies, and resonance parameters leaves the shape statistically compatible. The author further shows that on hydrogen, $\\theta_{\\rm COM}$ distributions from three different neutrino fluxes agree, so a high-purity hydrogen sample would allow direct cross-experiment comparison. The author flags two residual puzzles: $\\Delta^{++}$-only carbon events without FSI are not fully compatible with hydrogen, and 5 GeV neutrinos on hydrogen deviate from lower energies.","feed_headline":"A single angle isolates final-state effects in neutrino scattering","feed_subtitle":"The COM angle ignores nuclear initial state and neutrino energy, yet responds sharply to FSI.","key_machinery":"The central object is the proton--pion centre-of-momentum frame and the angle $\\theta_{\\rm COM}$ defined between the pion's COM-frame momentum and the lab-frame direction of $\\vec p_{\\rm sum} = \\vec p_p + \\vec p_\\pi$. The load-bearing relation is that without FSI the COM frame coincides with the $\\Delta^{++}$ rest frame, so $\\theta_{\\rm COM} = \\theta_{\\pi\\Delta}$; FSI makes the measured hadronic sum differ from the true resonance momentum, and that mismatch is what $\\theta_{\\rm COM}$ encodes. The companion quantity $E_{\\rm COM}$ is the total energy in the same frame, equal to the resonance rest mass when FSI is absent, and is used as a resonance-selection cut.","core_discovery":"When a neutrino excites a nucleon into a $\\Delta^{++}$ resonance, the resonance decays to $\\pi^+$ and $p$; in the resonance rest frame the pion decay angle $\\theta_{\\pi\\Delta}$ is an intrinsic property of the resonance. In a nuclear target, FSI changes the measured hadron momenta, so the true resonance frame is not directly accessible. Boosting the measured proton--pion system into its own centre-of-momentum frame using $\\vec p_{\\rm sum} = \\vec p_p + \\vec p_\\pi$ defines $\\theta_{\\rm COM}$, the angle between the pion's momentum in that frame and the direction of $\\vec p_{\\rm sum}$ in the lab. In the absence of FSI, $\\vec p_{\\rm sum}$ equals the resonance momentum and $\\theta_{\\rm COM}$ equals $\\theta_{\\pi\\Delta}$; with FSI, the deviation is a direct measure of final-state interactions. Because $\\theta_{\\pi\\Delta}$ is independent of the resonance momentum and of the nuclear initial state, the paper argues $\\theta_{\\rm COM}$ inherits those independencies, and because it uses only hadronic momenta it is practically free of neutrino-energy reconstruction uncertainties. The companion variable $E_{\\rm COM}$, the total energy in the COM frame, equals the resonance mass in the FSI-free limit, so a cut at $E_{\\rm COM} < 1330$ MeV selects $\\Delta^{++}$-dominated events and suppresses higher-resonance contamination; for high-purity hydrogen selections, $\\theta_{\\rm COM}$ distributions are statistically compatible across different experimental fluxes.","pith_inferences":["If the central claim holds, $E_{\\rm COM}$ far from the resonance mass flags FSI-distorted events, so an $E_{\\rm COM}$ cut could serve as a model-independent way to select near-detector events with minimal FSI and improve hydrogen-sample purity; the paper reports preliminary support for this but leaves it for future work.","The same variable could be used to compare neutrino and antineutrino data directly, since the COM frame is built only from hadrons and does not require the incoming neutrino energy; the paper does not explore this.","The residual discrepancies the paper reports ($\\Delta^{++}$-only carbon FSI-off vs hydrogen, and 5 GeV neutrinos on hydrogen) suggest a small production--decay correlation or nuclear binding effect; if real, it would need a correction term, but it is concentrated at energies that contribute little to current oscillation beams.","A natural testable extension is to reanalyse published kinematic-imbalance data in the COM frame; because those data span different targets and fluxes, the exercise would provide an immediate check of the cross-experiment compatibility claim."],"forward_implications":["$\\theta_{\\rm COM}$ measurements can constrain FSI models in CC1$\\pi$1p events without retuning when initial-state models change, because the variable is insensitive to IS modelling.","A cut on $E_{\\rm COM}$ near the $\\Delta^{++}$ mass protects $\\theta_{\\rm COM}$ against resonance-model uncertainties even for higher-energy beams, by selecting $\\Delta^{++}$-dominated events.","On hydrogen targets, $\\theta_{\\rm COM}$ distributions from different experimental fluxes agree, so a high-purity neutrino--hydrogen selection enables direct cross-experiment comparison.","Comparing $\\theta_{\\rm COM}$ with and without the $E_{\\rm COM}$ cut can reveal the onset of higher resonances and, with suitable models, correlations among resonance production modes.","Because $\\theta_{\\rm COM}$ reconstruction uses only proton and pion momenta, its measurement is decoupled from neutrino-energy reconstruction and thus from flux-related systematic uncertainties."],"supporting_citations":[{"why":"Supplies the Monte Carlo generator and event tunes that produce all simulated νμCC1π1p samples.","marker":"[29, 30]"},{"why":"Describes the hA and hN final-state interaction models whose comparison drives the central FSI-sensitivity test.","marker":"[41]"},{"why":"Defines the reconstructed Adler angle, the benchmark variable that θ_COM is compared against for initial-state and flux robustness.","marker":"[23]"},{"why":"Provides the TKI-tuned hA model whose disagreement with the default hA demonstrates θ_COM sensitivity to FSI.","marker":"[17]"},{"why":"Establishes a practical high-purity neutrino-hydrogen selection, the basis for the cross-experiment comparison claim.","marker":"[44]"},{"why":"Introduces the transverse kinematic imbalance variables that motivate the use of constructed hadronic variables to expose nuclear effects.","marker":"[14, 15]"}],"fun_headline_variants":["COM angle reveals FSI without flux or nuclear-state bias","Single COM angle isolates final-state interactions cleanly","Pion angle in CM frame isolates FSI independent of flux","COM angle directly probes final-state interactions in neutrino scattering","New angle variable strips away nuclear initial state to expose FSI"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The argument rests on the assumption that the pion decay angle in the resonance rest frame does not depend on how the resonance was produced, on the neutrino energy, or on the nuclear initial state; if production and decay are correlated, or if the nuclear medium alters the decay, then $\\theta_{\\rm COM}$ changes cannot be attributed to FSI alone.","fun_headline_variants_meta":{"raw":{"variants":["COM angle reveals FSI without flux or nuclear-state bias","Single COM angle isolates final-state interactions cleanly","Pion angle in CM frame isolates FSI independent of flux","COM angle directly probes final-state interactions in neutrino scattering","New angle variable strips away nuclear initial state to expose FSI"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.001221,"raw_usage":{"total_tokens":5038,"prompt_tokens":978,"completion_tokens":4060,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":594,"completion_tokens_details":{"reasoning_tokens":3980}},"tokens_in":594,"tokens_out":4060,"duration_ms":28951,"temperature":1.0,"reasoning_tokens":3980,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-10T20:13:12.618690+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Generate $\\Delta^{++}$-only CC1$\\pi$1p events on hydrogen and carbon with FSI switched off using much larger statistics than the 600,000-event samples in this study; if the $\\theta_{\\rm COM}$ distributions remain incompatible at the level seen here ($\\chi^2/{\\rm NDF} = 32/8$), or if the 5 GeV hydrogen distribution keeps its $\\chi^2/{\\rm NDF} = 95/8$ deviation, the claimed independence from initial state and neutrino energy is falsified.","supporting_citations":[{"cited_title":"On the measurement of Adler angles in charge current single pion neutrino-nucleusinteractions","cited_arxiv_id":"1511.00501","evidence_quote":"Defines the reconstructed Adler angle, the benchmark variable that θ_COM is compared against for initial-state and flux robustness."},{"cited_title":"Cai et al.(MINERvA), Measurement of the axial vec- tor form factor from antineutrino–proton scattering, Na- ture 614, 48 (2023)","cited_arxiv_id":null,"evidence_quote":"Establishes a practical high-purity neutrino-hydrogen selection, the basis for the cross-experiment comparison claim."}],"review_version":1}