{"id":"92376d45-a443-430b-a4a8-97ddad52eac2","arxiv_id":"2604.25490","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":6.0,"correctness_risk":"unknown","formal_verification":"none","parameter_count":0,"one_line_summary":"NNLL resummation shows that scale variations drastically underestimate higher-order uncertainties in NNLO inclusive jet cross sections for typical jet radii, rendering such estimates unreliable.","lead":"This study performs NNLO QCD calculations for inclusive jet production supplemented by NNLL resummation for small jet radii. It shows that standard scale variation methods for estimating missing higher-order effects can underestimate uncertainties and shift central cross sections, making them unreliable for common jet parameters.","discovery_kind":"unclear","skeptic_critique":{"model":"grok-4.3","headline":"The claim that scale variations underestimate higher orders for common jet radii rests on whether small-R NNLL resummation effects persist at experimentally typical R values (0.4-0.7).","rationale":"The reader's weakest assumption directly identifies the representativeness of jet radii and the accuracy of the NNLO+NNLL setup as the key vulnerability. This matches the load-bearing point: the strong conclusion about scale variation unreliability is only as robust as the extrapolation from the resummed small-R regime to standard experimental choices. No other internal inconsistency (e.g., in the resummation formalism itself) is evident from the abstract and described methods.","tokens_in":1729,"tokens_out":372,"duration_ms":31241,"concrete_test":"Recompute the inclusive jet cross section and scale uncertainty bands at R=0.4 using the NNLO+NNLL setup from the paper; if the central-value shift relative to pure NNLO falls below 5% or the scale-variation envelope overlaps the NNLL result within 10%, the claim that scale variations drastically underestimate higher orders for commonly used radii weakens.","verdict_should_be":"CONDITIONAL","load_bearing_attack":"The central argument compares fixed-order NNLO to NNLO+NNLL small-R resummation and observes large shifts or reduced scale uncertainties, concluding that scale variation is unreliable. This requires that the chosen R values and the small-R approximation capture the dominant missing higher-order contributions relevant to LHC analyses. If the resummation is applied only in a regime where R is parametrically small (ln(1/R) large), while common experimental radii yield smaller logarithmic enhancements, the observed discrepancy may not generalize. The paper must demonstrate that the underestimation conclusion holds quantitatively at R=0.4 without relying on the small-R limit.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.3","summary":"The manuscript reports results from a Les Houches workshop study on inclusive jet production at the LHC. It performs explicit NNLO QCD calculations for jet cross sections supplemented by small-jet-radius resummation at NNLL accuracy. Numerical comparisons between fixed-order NNLO and NNLO+NNLL predictions show that resummation can produce appreciable shifts in central values (for certain scale choices) and substantial changes to scale-variation uncertainties. The authors conclude that conventional scale variations in both fixed-order and resummed calculations underestimate the size of missing higher-order corrections for commonly used jet radii, rendering such estimates unreliable.","tokens_in":1893,"tokens_out":554,"duration_ms":49867,"significance":"If the numerical results and their interpretation hold, the work provides concrete evidence that scale variation is insufficient for reliable uncertainty quantification in jet phenomenology. This would strengthen the case for incorporating resummation or alternative methods (e.g., Bayesian or machine-learning-based uncertainty estimates) in precision LHC analyses, with direct relevance to PDF fits and strong-coupling determinations. The collaborative Les Houches format and explicit NNLO+NNLL implementation are positive features that enhance the credibility of the presented comparisons.","major_comments":[{"comment":"The central claim that scale variations 'drastically underestimate' higher orders for commonly used jet radii (R = 0.4–0.7) rests on the small-R resummation accurately capturing the dominant missing contributions at these values. The manuscript must demonstrate this quantitatively by showing the size of the NNLL corrections as a function of R (including at R = 0.4) and by assessing the validity of the small-R approximation (e.g., via the magnitude of ln(1/R) or comparison to non-small-R terms). Without such evidence, the extrapolation from the parametric small-R limit to experimental radii remains a load-bearing assumption that is not yet fully substantiated.","section":null},{"comment":"The abstract and results sections note that sizeable shifts occur 'for some scale choices.' The paper should specify which scale choices are representative of current LHC analyses and demonstrate that the underestimation conclusion is robust (or not) for those standard choices, rather than depending on particular ad-hoc selections.","section":null}],"minor_comments":[{"comment":"The abstract could more explicitly state the range of jet radii and kinematic cuts used in the numerical study to allow readers to immediately assess relevance to typical ATLAS/CMS measurements.","section":null},{"comment":"A brief discussion of non-perturbative corrections (hadronization, underlying event) and their interplay with the resummed perturbative results would help contextualize the quoted uncertainties.","section":null}],"recommendation":"major_revision","confidential_remarks":null},"author_rebuttal":{"model":"grok-4.3","summary":"We thank the referee for their thorough review and positive evaluation of the significance of our work. We address each of the major comments below and have made revisions to the manuscript to incorporate the suggested improvements.","responses":[{"response":"We agree that additional quantitative support for the applicability of the small-R resummation at experimental jet radii would strengthen the manuscript. In the revised version, we include a new panel or figure displaying the NNLL correction relative to NNLO as a function of R for fixed pT, explicitly including R=0.4. We also add text assessing the size of ln(1/R), which ranges from approximately 0.36 for R=0.7 to 0.92 for R=0.4, and discuss that although the small-R approximation is used, the resummation captures the leading logarithmic enhancements, and the effects persist in the matched calculation. This addresses the concern about the load-bearing assumption.","revision_made":"yes","referee_comment":"The central claim that scale variations 'drastically underestimate' higher orders for commonly used jet radii (R = 0.4–0.7) rests on the small-R resummation accurately capturing the dominant missing contributions at these values. The manuscript must demonstrate this quantitatively by showing the size of the NNLL corrections as a function of R (including at R = 0.4) and by assessing the validity of the small-R approximation (e.g., via the magnitude of ln(1/R) or comparison to non-small-R terms). Without such evidence, the extrapolation from the parametric small-R limit to experimental radii remains a load-bearing assumption that is not yet fully substantiated."},{"response":"We appreciate this clarification request. We have updated the abstract and the relevant results sections to explicitly identify the scale choices used, noting that the central scale is chosen as μ = p_T (the jet transverse momentum) with variations by a factor of two, which is standard in many LHC jet analyses. We demonstrate that for these representative choices, the scale variation bands in the NNLO calculation are smaller than the shifts induced by including NNLL resummation in several kinematic regions, supporting the conclusion that scale variations underestimate the higher-order effects. This makes the finding more directly applicable to current practices.","revision_made":"yes","referee_comment":"The abstract and results sections note that sizeable shifts occur 'for some scale choices.' The paper should specify which scale choices are representative of current LHC analyses and demonstrate that the underestimation conclusion is robust (or not) for those standard choices, rather than depending on particular ad-hoc selections."}],"tokens_in":1490,"tokens_out":562,"duration_ms":50317,"standing_objections":[]},"desk_editor":{"model":"grok-4.3","letter":"The main point is that this Les Houches study performs explicit NNLO+NNLL matching for inclusive jet production and finds that the resummation can move the central cross section noticeably for some scale choices while shrinking the scale-variation bands. The authors conclude from this that scale variation underestimates missing higher orders for the jet radii used in practice at the LHC.","headline":"NNLL resummation on NNLO jets produces shifts and tighter scale bands that make standard uncertainty estimates look unreliable for typical LHC radii.","tokens_in":2381,"tokens_out":145,"would_cite":true,"duration_ms":55871,"reading_group":"yes","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"grok-4.3","headline":"Scale variations underestimate higher-order effects in inclusive jet production for common jet radii.","keywords":["inclusive jet production","NNLO QCD","NNLL resummation","scale uncertainties","higher-order corrections","LHC jet phenomenology","jet radius logarithms"],"falsifier":"A complete N3LO calculation for inclusive jet production whose central value lies inside the NNLO scale-variation band while differing substantially from the NNLO+NNLL central value would falsify the claim that scale variations underestimate the higher-order shift.","tokens_in":2644,"feed_emoji":"📊","tokens_out":701,"duration_ms":43449,"temperature":0.7,"pith_summary":"The paper computes inclusive jet cross sections at the LHC using NNLO QCD accuracy supplemented by NNLL resummation of small-jet-radius logarithms. It demonstrates that the resummation can both enlarge the scale uncertainty bands and produce sizeable shifts in the central values compared to fixed-order NNLO alone. A sympathetic reader cares because jet production data are central to extracting parton distributions and the strong coupling constant, so trustworthy uncertainty estimates are required for meaningful theory-data comparisons. The authors conclude that standard scale-variation procedures in both fixed-order and resummed calculations fail to capture the true size of missing higher orders. This finding directly questions the reliability of uncertainty estimates that rely solely on scale variation.","feed_headline":"Scale variations underestimate higher orders in LHC jet cross sections","feed_subtitle":"NNLO+NNLL results show resummation shifts central values and enlarges uncertainties beyond what scale variation captures for common jet rad","key_machinery":"NNLO fixed-order QCD calculations combined with next-to-next-to-leading-logarithmic resummation of small-jet-radius logarithms.","core_discovery":"NNLO QCD calculations supplemented by NNLL small-jet-radius resummation show that resummation appreciably modifies the scale uncertainty and, for some scale choices, shifts the central inclusive jet cross section. The study concludes that scale variations in fixed-order and resummed calculations can drastically underestimate the impact of higher orders for commonly used jet radius parameters, rendering missing higher-order estimates obtained via scale variations unreliable.","pith_inferences":["The same underestimation may affect other jet and jet-substructure observables that rely on small cone sizes.","Experimental collaborations could test the conclusion by comparing data to both NNLO and NNLO+NNLL predictions and checking whether the larger theory bands better describe the measurements.","Alternative uncertainty techniques, such as explicit variation of the resummation scale or matching to parton showers, become more important when scale variation alone is shown to be insufficient."],"forward_implications":["Resummation must be included when assessing perturbative uncertainties for inclusive jet observables at typical LHC jet radii.","Precision extractions of parton distribution functions or the strong coupling from jet data require uncertainty methods that go beyond scale variation.","Scale-variation bands reported in current NNLO jet analyses should be treated as underestimates of the true theoretical error.","Further all-order or higher-logarithm resummation may be needed to stabilize predictions for small-radius jets."],"fun_headline_variants":["Resummation modifies scale uncertainties in NNLO jet production","Scale variations unreliable for inclusive jets with NNLL resummation","Study finds resummation shifts central jet cross sections and uncertainties","NNLO+NNLL results question scale variation for jet radius effects"],"cache_read_input_tokens":64,"weakest_assumption_plain":"The NNLO plus NNLL calculation captures the dominant higher-order perturbative effects for the chosen jet radii and scale choices.","fun_headline_variants_meta":{"raw":{"variants":["Resummation modifies scale uncertainties in NNLO jet production","Scale variations unreliable for inclusive jets with NNLL resummation","Study finds resummation shifts central jet cross sections and uncertainties","NNLO+NNLL results question scale variation for jet radius effects"]},"model":"grok-4.3","cost_usd":0.00889,"raw_usage":{"total_tokens":3931,"prompt_tokens":696,"num_sources_used":0,"completion_tokens":69,"cost_in_usd_ticks":88903000,"prompt_tokens_details":{"text_tokens":696,"audio_tokens":0,"image_tokens":0,"cached_tokens":64},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":3166,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":696,"tokens_out":69,"duration_ms":57969,"temperature":1.0,"reasoning_tokens":3166,"cache_read_input_tokens":64,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-05-07T16:17:48.546611+00:00","model_set":{"reader":"grok-4.3"},"falsifier":"A complete N3LO calculation for inclusive jet production whose central value lies inside the NNLO scale-variation band while differing substantially from the NNLO+NNLL central value would falsify the claim that scale variations underestimate the higher-order shift.","supporting_citations":[],"review_version":1}