{"id":"1dac7a55-49f7-4d0c-be3a-5bf2b8d3f6be","arxiv_id":"2501.06072","paper_version":1,"verdict":"UNVERDICTED","confidence":"HIGH","novelty_score":0.0,"correctness_risk":"low","formal_verification":"none","parameter_count":0,"one_line_summary":"A review of LHC top-associated dark matter searches, all reporting no significant excess.","lead":"This proceedings paper reviews recent LHC searches for dark matter produced together with top quarks, summarizing results from ATLAS and CMS using Run 2 data. It reports that no significant excess is seen and presents the resulting exclusion limits on dark matter and mediator masses.","discovery_kind":"review","skeptic_critique":{"model":"deepseek-v4-flash","headline":"No significant objection identified: the 'no excess' claim is a faithful review summary; the 2σ excesses reported in the text are below the conventional significance threshold.","rationale":"The reader's verdict UNVERDICTED is appropriate for a proceedings without new results or artifacts. The reader's weakest_assumption concerned the correctness of the underlying ATLAS/CMS background models; although true, this is not a weakness of the review itself, because the paper does not re-derive those estimates and its claim is explicitly a report of the collaborations' results. I looked for an internal inconsistency in the central claim. The 1-2σ excesses mentioned in Secs. 2.3, 3.3, and 3.4 are the only candidates; they do not invalidate 'no statistically significant excess' under standard HEP thresholds, though the threshold is left implicit. A single verification step against the original papers would settle the wording question, but no load-bearing concern is identified and the verdict remains unchanged.","tokens_in":11989,"tokens_out":5134,"duration_ms":50211,"concrete_test":"Check the source analyses cited for the largest local significances (ATLAS JHEP 07 250, CMS-PAS-EXO-22-014, and CMS-PAS-SUS-23-004 for mono-top) and compare them with any quoted global significances or trials factors. If any reported local significance exceeds 3σ, or any global significance exceeds the conventional 5σ discovery threshold, the abstract's blanket 'no statistically significant excess' would need qualification; otherwise the claim stands as written.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The paper is a conference proceedings summarizing published/PAS analyses, and its central claim is that no search sees a statistically significant excess. The body reports small excesses of about 2σ in the ATLAS stop-to-top-charm search (Sec. 3.3) and in the CMS single-top/t-tbar+DM search (Sec. 3.4), plus a 1σ excess in the CMS mono-top search (Sec. 2.3). These are not internally inconsistent with the abstract: in HEP usage 'statistically significant' is reserved for much larger local/global significances, so a 1-2σ local excess does not contradict 'no statistically significant excess'. The claim's correctness ultimately depends on the original ATLAS/CMS background modeling and systematic assessments, but that is an external dependency inherent to any review, not a load-bearing flaw in the argument presented here. The only real caveat is that the significance threshold is never defined in the paper, so a non-specialist reader could misread 'no statistically significant excess' as 'no excess at all'; this is a clarity issue, not a correctness issue.","agreement_with_reader":"disagree"},"referee_report":{"model":"deepseek-v4-flash","summary":"This paper is a conference proceedings for TOP2024 summarizing recent ATLAS and CMS searches for dark matter produced in association with top quarks at the LHC. It covers mono-top searches, ttbar+DM searches including a CMS measurement of ttbar neutrino kinematics, an ATLAS search for stop squarks decaying to top-charm plus neutralino, and a combined CMS search for single-top+DM and ttbar+DM. The central claim, stated in the abstract and conclusion, is that no statistically significant excess is observed in any of these searches, although local excesses of about 1–2σ are reported in several channels (Sections 2.3, 3.3, and 3.4).","tokens_in":12145,"tokens_out":4760,"duration_ms":41803,"significance":"If taken at face value, the manuscript provides a timely and accurate summary of the current experimental status of top-associated dark matter searches using the full Run 2 dataset. Its main value is as a compact reference for the community, and it correctly identifies the most sensitive analyses and reports the small excesses without overinterpreting them. The author is careful to distinguish observed limits from expected limits and to note differences between the ATLAS and CMS strategies. As a review article it is reliable and well referenced, and the transparent reporting of the 1–2σ excesses is a credit to the author.","major_comments":[],"minor_comments":[{"comment":"The comparison of ATLAS and CMS limits contains a garbled sentence: “the for a coupling to DM of 0.25 and a DM mass of 1 GeV” should be rephrased to refer to the quark coupling and the intended parameter point, since the preceding text states that the CMS scan uses a quark coupling of 0.25 while the ATLAS scan uses 0.5.","section":"Section 2.3"},{"comment":"The sentence “there is an excess of with a significance of 2 σ” contains a grammatical error; it should read “there is an excess with a significance of 2σ”.","section":"Section 3.3"},{"comment":"The caption for the second Feynman diagram in Figure 10(b) contains leftover placeholder text (“Figure 31: Diagram 30” and “Figure 32: Diagram 31”) and should be replaced with a proper caption.","section":"Figure 10(b) caption"},{"comment":"The phrase “no statistically significant excess” is not defined. Since the body reports local excesses of about 2σ in Sections 3.3 and 3.4, the author should either define the significance threshold used (e.g., 5σ for discovery) or explicitly state that no excess exceeds 2σ local significance, to avoid ambiguity for non-specialist readers.","section":"Abstract and Section 4"},{"comment":"The statement that the ~2σ excess “is consistent with all mediator masses considered” is an over-interpretation; a background fluctuation is also consistent with all mediator masses. It would be safer to say that the excess is not statistically significant and shows no strong mass preference.","section":"Section 3.4"},{"comment":"The text claims that the new ATLAS analysis “only achieves the same level of sensitivity for the compressed region and slightly less for very boosted topologies” compared to the previous analysis; a quantitative statement (e.g., from the limit plot) would help support this comparison.","section":"Section 3.2"}],"recommendation":"minor_revision","confidential_remarks":"The manuscript is a typical conference proceedings and the central claim is sound. The minor issues identified are presentation-level and can be addressed by the author without further review. No concerns about novelty or scope."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Quick take: this is a conference proceedings summary, not a research paper. It covers five ATLAS/CMS searches for dark matter produced with top quarks using full Run 2 data, and it does exactly what a proceedings summary should do: it lays out the signal topologies, the background estimation strategies, and the resulting limits, and it is honest about the small excesses. If you need a one-stop orientation to this corner of the LHC DM program, this is a decent place to start.\n\nWhat it does well: the organization is clear (mono-top, ttbar+DM, stop-to-top-charm, combined t+DM and ttbar+DM), the descriptions of the ML taggers and control-region designs are accurate at the level of a summary, and the paper does not oversell. The abstract says no statistically significant excess, and the body openly reports a 1-sigma excess in the CMS mono-top search and ~2-sigma excesses in the ATLAS stop-to-top-charm search and the CMS t+DM/ttbar+DM search. Those are consistent with the abstract, but the paper never defines what it means by 'statistically significant'—a non-specialist could easily read 'no significant excess' as 'no excess at all.' That is a clarity issue, not a correctness issue.\n\nSoft spots: the obvious one is that there is no raw data, no likelihood information, and no statistical detail, so the 'no excess' claim is entirely a reflection of the original ATLAS and CMS analyses. For a proceedings, that is normal; it does mean independent verification is impossible here, and the value of the paper hinges on the reliability of the cited PAS papers and JHEP articles. The citation pattern is appropriate—no self-citation problem, since the author is a collaboration member summarizing those collaborations' work. There are also minor typos ('an is instead', 'masive', 'faction') that a copy edit would catch, and the figures are sometimes dense, but none of that undermines the content.\n\nThe central argument—that the current searches show no significant excess and set limits up to ~3 TeV on mediators and ~1.2 TeV on stops—holds as a summary. It is not new, but it does not pretend to be. The paper is a faithful review, and the stress-test concern about the 2-sigma excesses is unfounded; the text is careful to label them as small. If I have a substantive criticism, it is that the paper could have spelled out the significance threshold explicitly and added a sentence noting that local excesses at the 1–2 sigma level are expected fluctuations, to forestall misreading. That is a minor fix.\n\nWho is this for? A reader who wants a recent snapshot of top-associated DM searches without digging through five separate PAS notes and papers. It deserves a serious referee in the sense that a careful check of the summaries against the cited analyses would be worthwhile, but it should not be held to the standard of a new research result. I would accept it for peer review as a conference proceedings, and if I were editing, I'd request the explicit significance definition and a copy edit, then likely accept.","headline":"A well-written conference summary of recent ATLAS/CMS top-associated DM searches; no new physics, but an accurate and honest review that correctly flags its own caveats.","tokens_in":12593,"tokens_out":1619,"would_cite":false,"duration_ms":18140,"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":"Across ATLAS and CMS searches for dark matter produced with top quarks at the LHC, no statistically significant excess is observed.","keywords":["dark matter","top quark","LHC","ATLAS","CMS","missing transverse momentum","supersymmetry","mono-top signature"],"falsifier":"A measurement that found the predicted $t\\bar{t}$ or $Z\\to\\nu\\bar{\\nu}$ background rates in the high-$p_{\\mathrm{T}}^{\\mathrm{miss}}$ signal regions to be off by more than the quoted systematic uncertainties, or an independent reanalysis of the same Run 2 data that produced a signal-like excess above 5 $\\sigma$, would refute the no-excess claim.","tokens_in":11794,"feed_emoji":"🌌","tokens_out":6158,"duration_ms":54890,"temperature":0.7,"pith_summary":"This proceedings paper summarizes the latest ATLAS and CMS searches for dark matter produced together with top quarks at the LHC, using the full 13 TeV Run 2 dataset collected from 2015 to 2018. The searches cover mono-top production, dark matter with a top-quark pair, and stop squarks decaying to tops plus neutralinos, and they combine deep neural network taggers with data-driven background estimates. The central claim is that none of these searches observes a statistically significant excess over the Standard Model background. If correct, the paper gives an accurate map of the currently excluded parameter space, including mediator masses up to roughly 3 TeV in mono-top models and stop squark masses up to roughly 1.2 TeV in benchmark supersymmetric scenarios.","feed_headline":"LHC top-tagged dark matter searches see no excess","feed_subtitle":"Run 2 data rule out mediator masses up to ~3 TeV and stop squarks up to ~1.2 TeV in benchmark models.","key_machinery":"The common handle is missing transverse momentum, $p_{\\mathrm{T}}^{\\mathrm{miss}}$, the negative vector sum of all visible transverse momenta, which is attributed to the invisible dark matter recoiling against top quarks. Top quarks are identified as large-radius jets using deep neural networks: ATLAS applies a DNN jet tagger and CMS uses particleNet, a graph neural network, to define top-enriched and top-depleted categories. Signal extraction relies on boosted decision trees (XGBoost in ATLAS) and dedicated neural networks per signal, while backgrounds such as $t\\bar{t}$, $Z\\to\\nu\\bar{\\nu}$ and $W$+jets are constrained by control regions linked to the signal regions by transfer factors, and the topness variable suppresses dileptonic $t\\bar{t}$ backgrounds.","core_discovery":"The paper's central claim is that, across all the presented ATLAS and CMS analyses of dark matter produced in association with a single top quark or a top-quark pair, no statistically significant excess over Standard Model expectation is seen in the full Run 2 LHC dataset. The strongest resulting limits exclude vector flavour-changing-neutral-current mediator masses up to about 3 TeV in the mono-top searches, and stop squark masses up to about 1.2 TeV in the search for stop pair production decaying to a top quark and a neutralino. Local excesses around one to two sigma appear in a few signal regions, such as the boosted region of the flavour-violating stop search and the CMS combined single-top plus ttbar search, but none reaches the threshold for evidence.","pith_inferences":["If the local 2$\\sigma$ excesses seen in the flavour-violating stop search and the CMS combined $t$+DM/$t\\bar{t}$+DM search persist with more data, a mediator near 200 GeV would be a natural interpretation; the current statistics cannot distinguish that from a fluctuation.","Since single-top plus DM cross sections fall more slowly with mediator mass than $t\\bar{t}$+DM, future mono-top analyses may become more competitive than pair-production searches at high mediator mass.","The pattern of replacing fixed analysis categories with signal-specific neural networks and combined resolved-plus-boosted top taggers could carry over to other compressed-spectrum searches, where boosted topologies are hardest to separate from background."],"forward_implications":["The thermal freeze-out WIMP window with order-one couplings is not confirmed in top-associated channels; vector FCNC mediator masses up to about 3 TeV are excluded in the mono-top searches.","Stop squark interpretations are constrained up to about 1.2 TeV for the decay $\\tilde{t}\\to t\\tilde{\\chi}^0_1$, and flavour-violating stops decaying to a top and a charm are bounded despite a localized 2$\\sigma$ excess.","For the simplified pseudoscalar $t\\bar{t}$+DM model, the single-lepton channel becomes the most sensitive, and combining it with the 0- and 2-lepton channels improves the overall reach.","At Run 3's higher collision energy of 13.6 TeV, sensitivity to high mediator masses should improve because the production cross sections grow with energy."],"supporting_citations":[{"why":"ATLAS search for a boosted top quark plus missing transverse momentum; supplies the mono-top results and mediator mass limits.","marker":"[5]"},{"why":"CMS search for dark matter with a single top quark; the second mono-top analysis summarized here.","marker":"[8]"},{"why":"ATLAS search for top pairs plus missing transverse momentum in the single-lepton channel; the improved analysis with dedicated neural networks and resolved top taggers.","marker":"[13]"},{"why":"ATLAS search for stop squarks decaying to a top, a charm and neutralinos; gives the flavour-violating limits and the 2 sigma boosted-region excess.","marker":"[15]"},{"why":"CMS combined search for dark matter with a single top or top pair; provides the multi-lepton-channel combination and its limits.","marker":"[16]"},{"why":"Previous ATLAS single-lepton search used as the sensitivity baseline for the improved ttbar+DM analysis.","marker":"[14]"},{"why":"Earlier ATLAS constraints on spin-0 ttbar+DM mediators used for comparison with the new limits.","marker":"[10]"},{"why":"CMS measurement of dileptonic ttbar dineutrino kinematics supporting the background modelling for ttbar+DM searches.","marker":"[11]"}],"fun_headline_variants":["Top-associated DM searches at LHC see nothing","LHC top+DM searches: no excess, limits to 3 TeV","Null result in top-quark dark matter searches","ATLAS and CMS exclude top-associated DM signals","Run 2: no dark matter with top quarks found"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The 'no significant excess' conclusion assumes that the ATLAS and CMS analyses model all Standard Model backgrounds, especially $t\\bar{t}$ and $Z/W$+jets, correctly and that their systematic uncertainties are accurate.","fun_headline_variants_meta":{"raw":{"variants":["Top-associated DM searches at LHC see nothing","LHC top+DM searches: no excess, limits to 3 TeV","Null result in top-quark dark matter searches","ATLAS and CMS exclude top-associated DM signals","Run 2: no dark matter with top quarks found"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000138,"raw_usage":{"total_tokens":1086,"prompt_tokens":811,"completion_tokens":275,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":427,"completion_tokens_details":{"reasoning_tokens":194}},"tokens_in":427,"tokens_out":275,"duration_ms":3328,"temperature":1.0,"reasoning_tokens":194,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-10T21:05:00.797141+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"A measurement that found the predicted $t\\bar{t}$ or $Z\\to\\nu\\bar{\\nu}$ background rates in the high-$p_{\\mathrm{T}}^{\\mathrm{miss}}$ signal regions to be off by more than the quoted systematic uncertainties, or an independent reanalysis of the same Run 2 data that produced a signal-like excess above 5 $\\sigma$, would refute the no-excess claim.","supporting_citations":[{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"CMS search for dark matter with a single top quark; the second mono-top analysis summarized here."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"CMS combined search for dark matter with a single top or top pair; provides the multi-lepton-channel combination and its limits."},{"cited_title":"Search for new phenomena with top quark pairs in final states with one lepton, jets, and missing transverse momentum in $pp$ collisions at $\\sqrt{s}$= 13 TeV with the ATLAS detector","cited_arxiv_id":"2012.03799","evidence_quote":"Previous ATLAS single-lepton search used as the sensitivity baseline for the improved ttbar+DM analysis."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"CMS measurement of dileptonic ttbar dineutrino kinematics supporting the background modelling for ttbar+DM searches."}],"review_version":1}