{"id":"064d2322-a44d-4ec9-9060-6f7524ac8ba2","arxiv_id":"2504.15882","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":5.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":3,"one_line_summary":"A simulation-based study finds that the 3 TeV CLIC could discover or exclude a vector-like B quark produced in pairs and decaying to bZ or bh with fully hadronic final states.","lead":"This paper simulates pair production of a heavy vector-like B quark at a future 3 TeV electron-positron collider (CLIC), using fully hadronic decays of boosted Higgs and Z bosons. It reports that CLIC could discover such a quark up to about 1.4 TeV with 5 inverse attobarns of data.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Section IV's 5-sigma discovery statement is not reproducible from the paper's own Tables I and II: at mB=1.4 TeV, Br=0.185 gives far below 5 sigma even if h and Z channels are combined.","rationale":"The reader correctly noticed that the conclusion misquotes significances and that the analysis depends on Delphes fast simulation. However, the sharper and more directly load-bearing issue is that the paper's flagship 5-sigma discovery claim (mB up to 1.4 TeV with Br>0.185) is inconsistent with the paper's own tabulated cut-flow results. This is not resolved by appealing to detector resolution; it fails even before any detector-smearing question is raised. I therefore kept the reader's CONDITIONAL verdict: the issue is serious but addressable by correcting the text/figures and documenting the significance treatment, so it does not require rejecting the entire phenomenological framework. The reason I mark agreement as partial rather than full is that the reader's identified weakest assumption was detector response, whereas I find the internal numerical contradiction in the discovery claim to be the most decisive point. The concrete test is deliberately chosen to settle the issue using only the paper's published tables, without needing new simulations or code.","tokens_in":8888,"tokens_out":15095,"duration_ms":149937,"concrete_test":"Recompute the 5-sigma discovery contour directly from Tables I and II. For each benchmark mass, scale the signal cross section by (Br/0.25)^2, keep the backgrounds fixed, and evaluate S/sqrt(S+B) for the h channel alone, the Z channel alone, and the two channels combined as (S_h+S_Z)/sqrt(S_h+B_h+S_Z+B_Z). Then determine the Br value at which the combined significance reaches 5 for mB=1.4 TeV. If that Br is above 0.185, or if no such Br exists below the maximum 0.25, the Section IV discovery statement and the corresponding Fig. 5 contour must be revised or the significance definition and channel-combination procedure must be stated explicitly and justified.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The most load-bearing concern is an internal inconsistency in the central discovery claim, not the Delphes detector model. Section IV states that a VLQ-B in the mass range 1-1.4 TeV with Br(B->bZ)>0.185 could be discovered at 5 sigma with 5 ab^-1. This is contradicted by the paper's own cut-flow tables. In Table II, at mB=1.4 TeV and Br=0.25, the Z-channel signal is 0.01018 fb (S=50.9 events) with total background 0.012922 fb (B=64.6 events), giving S/sqrt(S+B)=4.73. Scaling the signal by (0.185/0.25)^2=0.547 gives S~27.9 and significance ~2.90. The corresponding h-channel significance is ~2.39 (S~22.4, B~65.5). Combining the two independent channels gives sqrt(2.90^2+2.39^2)~3.76, far below 5 sigma. Even at mB=1.0 TeV, the Z-only significance at Br=0.185 is only ~4.39, below 5 sigma. The conclusion also misassigns the table entries: it reports 7.8148 (6.5169) for mB=1.2 (1.4) TeV in the h channel, whereas Table I assigns 7.8148 to 1000 GeV and 6.5169 to 1200 GeV. Because the 5-sigma contour in Fig. 5 is a central quantitative result and the paper provides no code, data, or significance-definition details to reproduce it, this is a load-bearing correctness issue, not merely a typographical one.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"The manuscript studies pair production of a weak-singlet vector-like B quark at the 3 TeV CLIC with 5 ab^-1, targeting B->bh and B->bZ decays in fully hadronic final states. The analysis uses MadGraph5 aMC@NLO, Pythia8, and Delphes3 with the VLC jet algorithm (R=1.0 for the h channel, R=0.8 for the Z channel), defines cut flows for both channels, and reports S/sqrt(S+B) significances for mB = 1.0, 1.2, and 1.4 TeV. The paper also presents 95% CL exclusion and 5-sigma discovery contours in the (mB, branching ratio) plane.","tokens_in":9258,"tokens_out":7585,"duration_ms":65113,"significance":"If the projections are correct, the fully hadronic boosted-jet approach offers a complementary and potentially competitive search for TeV-scale VLQ-B at CLIC, with the advantage of large hadronic branching ratios and a clean lepton-collider environment. The paper is transparent in its use of standard simulation tools and provides internally consistent cut-flow tables, which is a strength. However, the central discovery claim in the conclusion is contradicted by the paper's own tables, and the significance treatment lacks systematic uncertainties and a clear definition of the exclusion/discovery contours. These issues are load-bearing because the quantitative reach is the main result, so the paper needs substantial correction before the conclusions can be accepted.","major_comments":[{"comment":"The 5-sigma discovery statement in Section IV is inconsistent with the paper's own tables. For the Z channel at mB=1.4 TeV and Br(B->bZ)=0.25, Table II gives signal 0.01018 fb and total background 0.012922 fb after Cut-4. With L=5 ab^-1, S=50.9 and B=64.6, so S/sqrt(S+B)=4.73. If the branching ratio is lowered to 0.185, the signal scales as (0.185/0.25)^2=0.547 because both B and anti-B must decay to bZ, giving S≈27.9 and significance≈2.90. The corresponding h-channel significance is ≈2.39, so combining channels gives sqrt(2.90^2+2.39^2)≈3.76, well below 5. Even at mB=1.0 TeV, the Z-only significance at Br=0.185 is ≈4.39, also below 5. Consequently the claim that Br(B->bZ)>0.185 can be discovered across 1.0-1.4 TeV is contradicted by the reported cut-flow tables. The discovery contours in Fig. 5 and the conclusion must be recalculated, and the significance definition or the quoted Br threshold must be revised.","section":"Section IV, Tables I and II"},{"comment":"The benchmark significances quoted in the conclusion are misassigned. Section IV says 'Taking mB=1.2 TeV (1.4 TeV)... significance 7.8148 (6.5169)... in boosted higgs channel', but Table I lists 7.8148 for mB=1000 GeV and 6.5169 for 1200 GeV. For the Z channel, the text reports 'a significance 6.898 (6.3358)', whereas Table II lists 6.898 for 1000 GeV and 6.3358 for 1200 GeV. These misquotations make the mass dependence of the search appear weaker than it is and should be corrected; in particular, the 1400 GeV Z-channel significance is 4.728, not 6.3358.","section":"Section IV, Tables I and II"},{"comment":"The statistical treatment is under-specified. The quoted S/sqrt(S+B) is purely statistical; there is no systematic uncertainty on the background normalizations, which are significant after the final cuts (e.g., in the Z channel at 1.4 TeV, t-tbar contributes 0.01001 fb, comparable to the signal 0.01018 fb). The 95% CL exclusion and 5-sigma discovery contours in Fig. 5 are presented without stating the corresponding S/sqrt(S+B) thresholds or the procedure used to scan branching ratios (e.g., whether the signal is scaled by Br^2 and whether backgrounds are held fixed). The authors should specify the significance formula, include or justify omission of background systematics, and provide the numerical definition of the contours. Without this, the reach curves cannot be independently checked.","section":"Section III and Fig. 5"},{"comment":"The optimized cuts (HT>600, the mass windows 100bZ)>0.185 can be discovered over the full 1-1.4 TeV range is contradicted by Table II. At 1.4 TeV and Br=0.185, scaling the Table II signal by (0.185/0.25)^2 gives S~28, B~65, significance about 2.9 in the Z channel; combining with the h channel gives around 3.8, not 5. At 1.2 TeV the combined significance would be about 5.7, so the claim should be reworded to a mass range that stops near 1.2 TeV, or a corrected Fig. 5 should be provided. The other caveats are minor for this genre: no systematic uncertainties, cut thresholds tuned on the same samples, and Delphes-only detector modeling. None of that sinks the paper, but it should be stated clearly.\n\nFor whom: anybody who wants a quick, organized comparison of CLIC's reach for VLQ-B in hadronic channels against the LHC and HL-LHC. It deserves a serious referee; the central analysis looks sound, but the discovery claim and the misquoted table values must be corrected before publication.","headline":"Useful CLIC sensitivity projection for hadronic VLQ-B searches, but the Section IV discovery claim overstates the reach and the conclusion misquotes the paper's own tables.","tokens_in":9786,"tokens_out":4582,"would_cite":false,"duration_ms":38858,"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 projects that pair-produced vector-like B quarks decaying to bZ or bh can be discovered at the 3 TeV CLIC in fully hadronic channels with 5 ab^-1.","keywords":["vector-like B quark","CLIC","pair production","fat jets","boosted hadronic decays","exclusion limits","discovery prospects","new physics"],"falsifier":"Take the same event generation and cut flow but replace the fast detector model with a full simulation, or inflate the jet energy resolution by 20-30%, and recompute S/$\\sqrt$(S+B) for mB = 1.2 TeV at 5 $ab^{-1}$; if the Higgs and Z mass-window efficiencies fall enough to push the significance below 5, the paper's quoted reach overestimates the CLIC sensitivity.","tokens_in":8691,"feed_emoji":"⚛️","tokens_out":8317,"duration_ms":76928,"temperature":0.7,"pith_summary":"This paper projects that a 3 TeV CLIC running at 5 $ab^{-1}$ can search for a heavy vector-like B quark through pair production followed by B->bh or B->bZ, using fully hadronic decays of the Higgs or Z boson. Because the B quark is TeV-scale, the Higgs or Z is highly boosted and its decay products merge into a single fat jet, so the analysis clusters hadrons with a large jet radius and applies mass-window cuts. The projected 95% CL exclusions cover branching ratios down to about 0.107 in the boosted-Higgs channel and 0.116 in the boosted-Z channel, for masses between 1.0 TeV and roughly 1.48-1.49 TeV. A 5-$\\sigma$ discovery is projected for a B quark with mass between 1 and 1.4 TeV when Br(B->bZ) exceeds 0.185. The motivation is that exotic decay modes can reduce standard-model branching ratios and relax existing LHC bounds, so a lepton-collider search in hadronic channels provides complementary coverage.","feed_headline":"CLIC could discover vector-like B quarks up to 1.4 TeV","feed_subtitle":"Pair-produced B quarks decaying to bZ or bh leave fat jets; 5 ab^-1 would exclude masses near 1.5 TeV.","key_machinery":"The central mechanism is the boosted fat jet: at mB between 1 and 1.4 TeV and sqrt(s) = 3 TeV, the decay products of the Higgs or Z are collimated enough to be captured by large-radius jets using the Valencia Linear Collider algorithm with R = 1.0 for the Higgs channel and R = 0.8 for the Z channel. The discriminating variables are the reconstructed masses of the two leading jets, which must fall in the 100-150 GeV Higgs window or the 80-100 GeV Z window, together with an HT > 600 GeV cut and mass constraints pairing each fat jet with a light jet. The simplified effective Lagrangian for the singlet VLQ-B generates the signal, and the Goldstone-boson equivalence relation Br(B->bh) ~ Br(B->bZ) ~ (1-beta_new)/4 ties the two channels, allowing the results to be expressed as limits on the branching ratios after exotic decay modes are introduced.","core_discovery":"The paper argues that the clean e+e- environment of a 3 TeV CLIC with 5 $ab^{-1}$ makes the fully hadronic B-pair channel competitive with leptonic channels for a weak-isospin singlet vector-like B quark. For B->bh, after requiring at least four jets, HT > 600 GeV, the two leading mass-ordered jets in the 100-150 GeV Higgs window, light jets with mass below 70 GeV, and each fat-jet paired with a light jet to a combined mass above 300 GeV, the background falls to about 0.013 fb while the 1.0, 1.2, and 1.4 TeV signals retain 0.020, 0.0155, and 0.0082 fb, giving S/$\\sqrt$(S+B) values of 7.8, 6.5, and 4.0. For B->bZ with R = 0.8, a 80-100 GeV Z-mass window, and a combined two-light-jet mass cut above 100 GeV, the corresponding significances are 6.9, 6.3, and 4.7. On this basis the paper concludes that branching ratios down to 0.107 (bh channel) and 0.116 (bZ channel) can be excluded over 1000-1480 and 1000-1490 GeV respectively, and that a B quark with Br(B->bZ) above 0.185 is discoverable up to about 1.4 TeV.","pith_inferences":["The h and Z channels are analyzed separately; combining them in a single likelihood would likely push the 5-sigma discovery threshold below Br(B->bZ) = 0.185, a step the paper leaves implicit.","The paper fixes the benchmark Br(B->bh) = Br(B->bZ) = 0.25 for the cut flow and then rescales; an explicit scan over beta_new, the exotic branching fraction, would turn the two exclusion floors into direct constraints on models with extra scalars.","If the real CLIC detector has better jet mass resolution than the fast simulation, the same event selection would give higher significances and lower branching-ratio floors, meaning the quoted 0.107 and 0.116 values could be conservative.","Pair production of other vector-like quark species, such as a T or X quark, would produce similar boosted top/W/Z final states, so the method is likely transferable beyond the singlet-B case studied here."],"forward_implications":["With 5 ab^-1 at 3 TeV, the boosted-Higgs channel excludes Br(B->bh) in [0.107, 0.25] for mB from 1000 to 1480 GeV, and the boosted-Z channel excludes Br(B->bZ) in [0.116, 0.25] for mB from 1000 to 1490 GeV at 95% CL.","A singlet VLQ-B with mass between 1 and 1.4 TeV and Br(B->bZ) > 0.185 is discoverable at 5 sigma at the 3 TeV CLIC.","Fully hadronic channels reach about the same sensitivity as leptonic channels at CLIC, so they add coverage rather than merely duplicating existing searches.","If exotic decay modes reduce the standard branching ratios, the CLIC hadronic search can still probe standard decays in branching-ratio regions that are relaxed relative to current LHC bounds.","At a 10 TeV muon collider the pair-production cross section is s-channel suppressed, around 0.5 fb for mB = 1.5-2.5 TeV, so the same search is not promising there.","The same cut-based strategy, with shifted mass windows, would apply to other new-physics signals that produce pairs of boosted Higgs or Z bosons plus b-jets."],"supporting_citations":[{"why":"Supplies the effective Lagrangian for the singlet VLQ-B used to compute production and decay of the signal.","marker":"[49]"},{"why":"Provides the Goldstone-boson equivalence theorem that justifies the branching-ratio relations among B->bh, B->bZ, and B->tW.","marker":"[50]"},{"why":"Gives the observed LHC exclusion limits that the CLIC projections are compared against.","marker":"[19]"},{"why":"Provides the previous CLIC leptonic-channel VLQ search whose sensitivity is compared with the new hadronic results.","marker":"[38]"},{"why":"Demonstrates the large-radius fat-jet and substructure search strategy for fully hadronic VLQ decays at the LHC.","marker":"[55]"},{"why":"Extends the fat-jet search method and helps justify using large jet radii for boosted final states.","marker":"[56]"},{"why":"Generates the parton-level signal and background events used in the Monte Carlo study.","marker":"[57]"},{"why":"Performs parton showering and hadronization for the generated events.","marker":"[58]"},{"why":"Models the detector response for all event samples, determining the reconstructed jet masses and momenta.","marker":"[59]"},{"why":"Defines the large-radius jet clustering algorithm with which the fat jets are reconstructed.","marker":"[62]"}],"fun_headline_variants":["CLIC's hadronic search eyes ~1.4 TeV vector-like B","Fully hadronic B-pair search at CLIC reaches 1.4 TeV","Vector-like B discovery reach at CLIC: ~1.4 TeV","CLIC fat jets probe B quark masses to 1.4 TeV","3 TeV CLIC could discover B quark up to 1.4 TeV"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The projection rests on the fast detector simulation faithfully reproducing the mass resolution of large-radius jets at 3 TeV; if the real detector smears fat-jet masses more than that simulation does, the mass-window efficiencies and significances will be lower than quoted.","fun_headline_variants_meta":{"raw":{"variants":["CLIC's hadronic search eyes ~1.4 TeV vector-like B","Fully hadronic B-pair search at CLIC reaches 1.4 TeV","Vector-like B discovery reach at CLIC: ~1.4 TeV","CLIC fat jets probe B quark masses to 1.4 TeV","3 TeV CLIC could discover B quark up to 1.4 TeV"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000559,"raw_usage":{"total_tokens":2718,"prompt_tokens":1068,"completion_tokens":1650,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":684,"completion_tokens_details":{"reasoning_tokens":1543}},"tokens_in":684,"tokens_out":1650,"duration_ms":11931,"temperature":1.0,"reasoning_tokens":1543,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-16T11:14:52.102992+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Take the same event generation and cut flow but replace the fast detector model with a full simulation, or inflate the jet energy resolution by 20-30%, and recompute S/$\\sqrt$(S+B) for mB = 1.2 TeV at 5 $ab^{-1}$; if the Higgs and Z mass-window efficiencies fall enough to push the significance below 5, the paper's quoted reach overestimates the CLIC sensitivity.","supporting_citations":[{"cited_title":"Buchkremer, G","cited_arxiv_id":null,"evidence_quote":"Supplies the effective Lagrangian for the singlet VLQ-B used to compute production and decay of the signal."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Provides the Goldstone-boson equivalence theorem that justifies the branching-ratio relations among B->bh, B->bZ, and B->tW."},{"cited_title":"Aad et al","cited_arxiv_id":null,"evidence_quote":"Gives the observed LHC exclusion limits that the CLIC projections are compared against."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Provides the previous CLIC leptonic-channel VLQ search whose sensitivity is compared with the new hadronic results."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Demonstrates the large-radius fat-jet and substructure search strategy for fully hadronic VLQ decays at the LHC."},{"cited_title":"Choudhury, K","cited_arxiv_id":null,"evidence_quote":"Extends the fat-jet search method and helps justify using large jet radii for boosted final states."},{"cited_title":"Alwall, R","cited_arxiv_id":null,"evidence_quote":"Generates the parton-level signal and background events used in the Monte Carlo study."},{"cited_title":"Sj¨ ostrand, S","cited_arxiv_id":null,"evidence_quote":"Performs parton showering and hadronization for the generated events."},{"cited_title":"Boronat, J","cited_arxiv_id":null,"evidence_quote":"Defines the large-radius jet clustering algorithm with which the fat jets are reconstructed."}],"review_version":1}