{"id":"0217dcec-75c6-4e1b-ba37-20d3ee9454bd","arxiv_id":"2601.20023","paper_version":2,"verdict":"ACCEPT","confidence":"HIGH","novelty_score":4.0,"correctness_risk":"low","formal_verification":"none","parameter_count":1,"one_line_summary":"First CMS measurement of Υ(1S), Υ(2S), and Υ(3S) differential cross sections at √s=13.6 TeV, extending the pT reach from 100 to 200 GeV.","lead":"The CMS experiment measured how often three types of Upsilon mesons are produced in high-energy proton-proton collisions at 13.6 TeV, as a function of transverse momentum up to 200 GeV. The new data extend earlier measurements by a factor of two in momentum and will be used to test and refine QCD-based models of quarkonium production.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"MC-only L1 dimuon trigger correction for close muon pairs is the weakest link; a data/MC closure test with single-muon-triggered events would directly validate it.","rationale":"The reader identified the L1 dimuon trigger inefficiency as the weakest assumption; I agree that this is the most load-bearing assumption. The measurement is otherwise standard: cross sections are derived from a fit to dimuon mass spectra, acceptances are from simulation with polarization caveats, efficiencies are tag-and-probe from data, and results are provided in HEPData. The trigger correction is the only place where the central values rely on an MC-only ingredient with no direct data closure. However, the paper acknowledges this, assigns a sizable systematic uncertainty, and includes a sensitivity check by removing the affected events. That is an honest treatment of a known experimental limitation. A concrete data/MC closure test using single-muon-triggered events is feasible and would settle whether the 9% uncertainty is adequate, but its absence does not invalidate the measurement or overclaim the result. Therefore the reader's ACCEPT verdict should remain unchanged.","tokens_in":36262,"tokens_out":7243,"duration_ms":89395,"concrete_test":"Use the same single-muon-triggered data sample used for the tag-and-probe measurements: select events with two offline muons satisfying the analysis selection, measure the L1 dimuon trigger efficiency as a function of the muon-pair angular separation ΔR (or equivalently the Υ pT in each rapidity bin), and compare directly with the GEANT4 simulation prediction used for the correction factor. If the data/MC ratio deviates by more than the quoted uncertainty (up to 9%) in the low-ΔR region, the central values and their uncertainties would need revision; if consistent, the assumption is validated.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central cross sections depend on a correction factor for the L1 dimuon trigger inefficiency when the two muons are emitted close in angle/momentum (Section 3). This factor is evaluated using the GEANT4-based detector simulation only; no data-driven measurement of this inefficiency is reported. Section 5 assigns an uncertainty of up to 9% (at pT≈50 GeV) based on 'potential residual differences' between detector and simulation, and validates sensitivity by repeating the measurement after rejecting the affected events. However, that rejection test changes the event sample and only checks whether the result survives with larger statistical uncertainties; it does not validate the accuracy of the MC efficiency itself. If the simulation mis-models the close-pair inefficiency by more than the quoted 9%, the low-to-intermediate-pT cross sections (where the correction is largest) could be biased beyond the stated systematic uncertainty. The paper is transparent about this, but the concern remains that the largest systematic is not empirically anchored.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"This paper reports the first measurement of the Υ(1S), Υ(2S), and Υ(3S) differential production cross sections times the dimuon branching fraction in pp collisions at √s=13.6 TeV, using 37.4 fb⁻¹ of CMS data collected in 2022. The cross sections are measured as a function of pT from 20 to 200 GeV in two rapidity intervals, |y|<0.6 and 0.6<|y|<1.2. Signal yields are extracted from extended maximum likelihood fits to the dimuon invariant mass spectrum; muon efficiencies are measured with tag-and-probe, acceptances are obtained from GEANT4-based simulation with data-driven reweighting checks, and a dedicated correction accounts for L1 trigger inefficiency for close muon pairs. Numerical results are provided in Appendix A and in HEPData. The measurement extends the pT reach of the previous CMS 13 TeV measurement from 100 to 200 GeV and includes feed-down contributions from heavier bottomonia.","tokens_in":36494,"tokens_out":7938,"duration_ms":95107,"significance":"If the result holds, it provides a valuable new reference dataset for NRQCD global fits at a new collision energy and extends the high-pT reach of bottomonium production measurements. The analysis is careful and standard: the fit model is validated with alternative parametrizations, the tag-and-probe efficiencies are data-driven, the acceptance is checked by reweighting simulated spectra to the measured ones, and the systematic uncertainties are broken down by source. The availability of the numerical values in tables and HEPData is a clear strength that facilitates phenomenological reuse.","major_comments":[{"comment":"The systematic uncertainty on the L1 dimuon trigger inefficiency for close muon pairs is a load-bearing component, reaching about 9% at intermediate pT. The text states that this uncertainty reflects 'potential residual differences' between detector and simulation, but it does not explain how the quoted 1%–9% values are derived from the studies described. The rejection of low-efficiency events is a useful sensitivity check, but it does not validate the MC efficiency itself; the baseline and rejected results can agree while both share a common bias from an inaccurate correction. Please provide a more quantitative description of the uncertainty estimation, and discuss whether a data-driven closure test using single-muon-triggered events could be used to anchor this correction.","section":"Section 5"}],"minor_comments":[{"comment":"The text says the cross sections include feed-down from heavier bottomonia, but does not clarify whether non-prompt production from b-hadron decays is also included. Since the analysis does not use displacement requirements, the measurement is presumably inclusive; please state this explicitly.","section":"Section 3/6"},{"comment":"The systematic uncertainties in Tables A.1–A.3 are described as fully correlated, yet the ratios in Fig. 3 treat all uncertainties as uncorrelated. Please justify this conservative choice or account for the correlations between the 13.6 TeV and earlier CMS measurements where appropriate.","section":"Figure 3"},{"comment":"The text says the polarization scaling factors in Table A.4 can be interpolated to other polarization scenarios, but the interpolation formula is not given. Specify how the factors scale as a function of λθ (e.g., linear interpolation).","section":"Appendix A"},{"comment":"The fixed double-Crystal-Ball shape parameters are said to be validated with data integrated over pT. It would be helpful to show a few fit pull distributions or goodness-of-fit indicators, especially in the highest-pT bins where yields are small.","section":"Section 4"},{"comment":"Minor typographical issues: 'still provide a reasonably good description the data' should read 'description of the data'; the notation for the two rapidity ranges in the L1 uncertainty sentence is ambiguous and should be clarified.","section":"Section 5"}],"recommendation":"major_revision","confidential_remarks":"The measurement itself is sound and important, and the paper is well written. My major concern is the L1 trigger inefficiency systematic: it is the dominant source at intermediate pT, and the derivation of its uncertainty is not documented in sufficient detail. I believe this can be fixed with additional text rather than new analysis, but as written it is a load-bearing gap in the systematic evaluation. The other points are minor."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Quick take: this is a well-executed, incremental CMS cross-section measurement. It adds new data at 13.6 TeV with pT up to 200 GeV, roughly doubling the pT reach of the prior 13 TeV result. If you do quarkonium global fits, you'll want the tables. If you don't, nothing here changes the big picture.\n\nWhat's new: first measurement of Υ(1S,2S,3S) at 13.6 TeV in the dimuon channel, 37.4 fb^-1, two rapidity bins, pT 20-200 GeV. The analysis follows the established CMS recipe: extended maximum likelihood fits with double Crystal Ball signal shapes, tag-and-probe efficiencies, full simulation acceptance with data-driven reweighting checks, polarization correction table. The paper is clean and mostly transparent about systematic uncertainties. The numerical values are in HEPData, which matters for global fits.\n\nThe soft spot is exactly what the stress-test flags. The L1 dimuon trigger efficiency for pairs of muons that are close in angle/momentum is corrected using a factor from GEANT4 simulation only. No data-driven closure test with single-muon-triggered events is shown. The rejection test described in Section 5 removes the affected events and checks consistency, but that does not validate the MC model of the inefficiency itself; it only changes the sample. The assigned uncertainty, up to 9% around 50 GeV, covers 'potential residual differences' but is not empirically anchored. That is a real weakness. However, it is not a hidden one: the paper states it clearly, and the size of the effect is bounded by the uncertainty they assign. For a precision measurement this is the kind of thing a referee should push on, not a reason to reject.\n\nA second, minor issue: the acceptance systematic at low pT is about 10%, driven by the reweighting check. That is large but standard for this analysis. The NRQCD comparison in Fig. 2 is explicitly illustrative, which is the right call.\n\nI agree with the reader's verdict: accept. The result is what it claims to be, the data are public, and the main caveat is quantified. It will be a useful input to NRQCD LDME fits, though it is unlikely to resolve the long-standing polarization puzzle on its own.\n\nRecommendation: send to a competent referee, ask specifically about the L1 trigger efficiency and whether a data-driven cross-check could be added with the already-collected single-muon-triggered events. It deserves publication after that check is addressed.","headline":"A solid, incremental CMS measurement that extends Upsilon pT reach to 200 GeV at 13.6 TeV; the MC-only L1 trigger correction is the main caveat, but the paper is honest about it.","tokens_in":36931,"tokens_out":2201,"would_cite":true,"duration_ms":26283,"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":"This paper reports the first measurement of the production cross sections of the three bottomonium states Upsilon(1S), Upsilon(2S), and Upsilon(3S) in proton-proton collisions at a centre-of-mass energy of 13.6 TeV, differentially in transv","keywords":["bottomonium","Upsilon mesons","differential cross sections","NRQCD","quarkonium production","proton-proton collisions","dimuon channel","transverse momentum spectra"],"falsifier":"Compare the measured dimuon trigger efficiency as a function of the angular separation of the two muons, obtained from events recorded with single-muon triggers, against the efficiency predicted by the simulation. If the ratio differs from unity beyond the assigned uncertainty, the baseline cross sections, particularly near pT = 20 GeV, would need to be shifted.","tokens_in":36165,"feed_emoji":"⚛️","tokens_out":8854,"duration_ms":89275,"temperature":0.7,"pith_summary":"This paper reports the first measurement of the production cross sections of the three bottomonium states, Upsilon(1S), Upsilon(2S), and Upsilon(3S), in proton-proton collisions at a centre-of-mass energy of 13.6 TeV. The cross sections are measured differentially in transverse momentum from 20 to 200 GeV in two rapidity intervals, extending the reach of previous measurements by a factor of two. These data are meant to constrain non-relativistic QCD, particularly the long-distance matrix elements that parameterize how a heavy quark-antiquark pair becomes a meson. The measurement matters because it provides new constraints at an energy and momentum range not previously explored, and the numerical results are made available for global fits.","feed_headline":"Measured Upsilon cross sections at 13.6 TeV out to 200 GeV","feed_subtitle":"New bottomonium data in two rapidity bins sharpen tests of quarkonium production models.","key_machinery":"The analysis chain combines three elements: signal yields from an extended maximum likelihood fit of the dimuon mass spectrum using a double Crystal Ball shape for each resonance plus a polynomial background; an acceptance correction computed from simulated events, assuming unpolarized production; and a detection efficiency built from single-muon efficiencies measured from data with a tag-and-probe technique, multiplied by a correction for the hardware trigger inefficiency when the two muons are so close in angle and momentum that they may be misidentified as one track.","core_discovery":"The central result is the pT-differential cross section times branching fraction for each Upsilon state, extracted from fits to the dimuon invariant mass spectrum in 19 pT bins and two rapidity intervals. The measurement covers pT from 20 to 200 GeV, with the excited-to-ground-state ratios leveling off for pT above about 55 GeV. The cross sections include feed-down from heavier bottomonia and are quoted assuming unpolarized production, with tables provided to rescale to other polarization scenarios. Numerical values are given in an appendix and a data record.","pith_inferences":["If the high-pT plateau persists beyond 200 GeV, it would suggest that the three Upsilon states share a common short-distance production mechanism, with binding dynamics almost independent of the radial excitation.","The low-pT bins are the most sensitive to the simulation-based correction for the trigger inefficiency; a dedicated data-driven check using well-separated dimuons could either validate or bound the systematic uncertainty.","Because the cross sections are inclusive of feed-down, comparisons with theory will need to subtract feed-down from heavier states; a prompt-only extraction would be a natural follow-up."],"forward_implications":["The new measurements extend the pT reach of quarkonium cross sections to 200 GeV, roughly doubling the range previously explored.","The plateau in the Upsilon(2S)/Upsilon(1S) and Upsilon(3S)/Upsilon(1S) ratios at high pT gives a new observable that global NRQCD fits must reproduce.","The near-identical cross sections in the two rapidity intervals indicate that production is fairly flat across midrapidity.","The polarization conversion tables allow the results to be adapted to any future polarization measurement without redoing the analysis."],"fun_headline_variants":["Upsilon cross sections measured at 13.6 TeV up to pT 200 GeV","Upsilon ratios plateau above pT 55 GeV in pp collisions","New bottomonium cross sections from CMS at 13.6 TeV","Upsilon pT-differential cross sections flatten at high pT"],"cache_read_input_tokens":2304,"weakest_assumption_plain":"The central values rest on the assumption that the trigger efficiency for muon pairs that are close in angle and momentum is accurately described by the detector simulation; if the simulation mis-models this inefficiency, the low-pT cross sections could be biased by more than the quoted uncertainty.","fun_headline_variants_meta":{"raw":{"variants":["Upsilon cross sections measured at 13.6 TeV up to pT 200 GeV","Upsilon ratios plateau above pT 55 GeV in pp collisions","New bottomonium cross sections from CMS at 13.6 TeV","Upsilon pT-differential cross sections flatten at high pT"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000945,"raw_usage":{"total_tokens":3832,"prompt_tokens":661,"completion_tokens":3171,"prompt_tokens_details":{"cached_tokens":256},"prompt_cache_hit_tokens":256,"prompt_cache_miss_tokens":405,"completion_tokens_details":{"reasoning_tokens":3089}},"tokens_in":405,"tokens_out":3171,"duration_ms":23761,"temperature":1.0,"reasoning_tokens":3089,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-03T07:31:39.774860+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Compare the measured dimuon trigger efficiency as a function of the angular separation of the two muons, obtained from events recorded with single-muon triggers, against the efficiency predicted by the simulation. If the ratio differs from unity beyond the assigned uncertainty, the baseline cross sections, particularly near pT = 20 GeV, would need to be shifted.","supporting_citations":[],"review_version":1}