{"id":"d4556217-7eb7-4fbe-b5f2-b8be95a209b7","arxiv_id":"1908.08546","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":6,"one_line_summary":"No significant neutrino signal is found from HAWC-detected Galactic gamma-ray sources, and the team sets 90 percent confidence upper limits on their muon-neutrino flux.","lead":"Using eight years of IceCube data, the IceCube and HAWC collaborations searched for neutrinos from the gamma-ray sources HAWC maps across the Galactic plane and found no significant excess. The result places new upper limits on hadronic neutrino emission from these TeV sources, informing models of Galactic cosmic-ray acceleration.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Pre-trial p-values without trials correction leave the headline null claim formally unquantified; the quoted 2% for J1857+027 is one of five tests, and the paper never reports a post-trial p.","rationale":"I read the paper as a null-result search. The central claim is robust in the sense that eight years of IceCube track data do not show a significant neutrino excess matched to HAWC templates. The paper is transparent about its main physical assumption (hadronic gamma-ray origin) and even cites the TeV-halo alternative, so that assumption is a scope condition, not a hidden flaw. The weakest link is statistical: the only quantitative evidence bearing on the null claim is a pre-trial p of 2% from one of five tests. Because the paper never gives a trials-corrected p, a strict reader cannot verify the 'not statistically significant' statement. However, the likely size of the correction makes it improbable that the conclusion flips. Thus I would keep the reader's CONDITIONAL verdict and not escalate. The check I propose is a standard background-only Monte Carlo that would settle the issue.","tokens_in":5026,"tokens_out":10621,"duration_ms":106410,"concrete_test":"Run background-only pseudo-experiments through the exact five likelihood scans in Table 1, preserving the same HAWC templates and IceCube event selection, and record the minimum pre-trial p across the five tests in each realization. Report the fraction of realizations with min p <= 0.02; this is the trials-corrected p for the J1857+027 excess. If it is >0.05, the paper's 'not statistically significant' claim is confirmed; if it is <=0.05, the headline null claim would need to be revised. A simpler check: apply Bonferroni by multiplying the 0.02 by 5 and verify the result remains above the chosen threshold.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim is a non-detection: 'not statistically significant' (Section 4). The strongest numerical support is the J1857+027 region, with an excess of 36.7 neutrinos and a pre-trial p-value of 2%. But this p-value is explicitly pre-trial, and Table 1 reports five separate likelihood tests (plus a 20-source stacking search), so the interpretation of 'not statistically significant' depends on the multiplicity correction. The paper states only the pre-trial value and does not give the trials-corrected p-value. A simple Bonferroni correction for five tests would put the smallest p at about 10%, still above 5%, so the null conclusion is probably intact; however the actual trial factor is not just 5 if the template search includes a continuum of spatial weightings or if the 20-source stacking is counted. Without a post-trial p, the central statistical claim is formally not established as stated. This is a completeness/correctness risk in the significance statement, not in the detector methodology. The reader's hadronic-origin concern is real but explicitly acknowledged in Section 3 and does not affect the non-detection; the trial-correction issue is the more load-bearing gap.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper, an ICRC 2019 proceedings contribution from the IceCube and HAWC collaborations, searches for muon-neutrino emission from HAWC-detected Galactic TeV gamma-ray sources using eight years of IceCube Northern-sky track events. It reports a stacked likelihood search over 20 non-PWN sources from the 2HWC catalog and a template search using the HAWC gamma-ray morphology over the Northern plane plus three predefined regions (Cygnus, 2HWC J1908+06, and 2HWC J1857+027). None of the five tests reaches a significant excess; the largest excess is 36.7 neutrinos toward 2HWC J1857+027 with a pre-trial p-value of 2%. In the absence of a signal, the paper places 90% C.L. upper limits on the nu_mu + antinu_mu flux at 7 TeV for each hypothesis and compares them with the neutrino flux expected if the measured HAWC gamma rays are hadronic, using the conversion of Kappes et al. [15].","tokens_in":5244,"tokens_out":6770,"duration_ms":66736,"significance":"If the results stand, the paper provides a useful null result: eight years of IceCube muon-neutrino data do not yet show an association with HAWC TeV sources, and the reported upper limits begin to constrain the hadronic fraction of the gamma-ray emission under the pion-decay assumption. The analysis is anchored to external HAWC observations and to an external hadronic conversion model, so the search is not circular; the only fitted parameters are signal normalizations. The stacking likelihood follows standard and previously published IceCube methodology, which is a strength. The main limitation is that the statistical evidence is reported only through pre-trial p-values, so the central \"not statistically significant\" statement is not fully quantified; the hadronic assumption is acknowledged but should be attached explicitly to the limit interpretation.","major_comments":[{"comment":"The central claim that the observed excess is \"not statistically significant\" is supported only by pre-trial p-values. Table 1 lists five separate likelihood tests, and the most significant p-value is 0.02 for the 2HWC J1857+027 region. No trials-corrected p-value is reported anywhere. Since the same eight-year data set is used in five tests, some multiplicity correction is required before \"not statistically significant\" can be taken as a formal statement; a simple Bonferroni correction over the five reported tests would place the smallest p near 0.10. The conclusion may well survive the correction, but the paper needs to state the post-trial p-value or justify why no correction applies.","section":"Section 4, Table 1"},{"comment":"The 90% C.L. upper limits are presented as the main quantitative product, but no systematic uncertainties are included or discussed. The limits depend on IceCube detector response, angular resolution, and the HAWC flux map used for the template weighting, and these inputs can shift the limits by an amount that matters for the comparison with the predicted hadronic fluxes shown in Figs. 4 and 5. At minimum, a sentence stating the dominant systematics and whether the quoted limits include them is needed before the limits can be used as quantitative constraints.","section":"Section 4, Figs. 4 and 5"},{"comment":"The upper limits are interpreted as constraining the hadronic component of the gamma-ray emission, but this interpretation holds only under the assumption, stated in the abstract, that the measured HAWC gamma rays are of pion-decay origin. Section 3 explicitly notes that TeV halos provide a leptonic alternative for many of these sources. The paper should therefore state, at the point where the limits are compared with the hadronic prediction in Figs. 4 and 5, that the exclusion applies to the hadronic fraction only in the hadronic-scenario model; a leptonic origin would remove the predicted flux. The non-detection itself is unaffected, but the limit interpretation is conditional.","section":"Section 4 (template searches) and Section 5"}],"minor_comments":[{"comment":"The abstract says \"two analyses,\" while Section 4 describes five tests. Clarify that there are two analysis classes (stacking and template) with five source hypotheses.","section":"Abstract and Section 4"},{"comment":"The source is called \"2HWC J1908+06\" in Section 4, \"J1908+063 Region\" in Table 1, and \"MGRO J1908\" in Section 5. Use one designation consistently.","section":"Table 1 and Section 4"},{"comment":"\"The rational for identifying Galactic sources\" should be \"The rationale for identifying Galactic sources.\"","section":"Section 5"},{"comment":"\"an under fluctuation of background\" should be \"an underfluctuation of the background\" or \"a downward fluctuation of the background.\"","section":"Section 4"},{"comment":"Reference [13] is incomplete: the title of the proceedings contribution is missing and there is a stray comma after the authors. Please complete the reference.","section":"References"}],"recommendation":"major_revision","confidential_remarks":"This is a conference proceeding and reads as such; the pre-trial p-value issue is common in ICRC papers but should be fixed for a journal version. The paper is within the scope of astroparticle physics. The main request is to add the trials-corrected significance and a systematic-uncertainty statement; the hadronic caveat is already partially acknowledged and needs to be tied to the limit interpretation. I would not reject on the basis of the hadronic assumption, because the null result is independent of it."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Colleague,\n\nQuick take: this is a legitimate null result from the IceCube/HAWC groups, and the most interesting thing about it is the template search using HAWC's measured gamma-ray morphology rather than point-like assumptions. The central claim—no significant neutrino excess from the 2HWC non-PWN sources or the three regions—holds up. The 2% pre-trial p for J1857+027 would not survive a modest trial correction across the five tests; Bonferroni puts it around 10%, so 'not significant' is the right call, though the paper should have said so.\n\nWhat's new: applying the standard IceCube stacking likelihood to a HAWC-selected source list and weighting by the gamma-ray flux map is a reasonable new combination, and the upper limits on muon-neutrino flux versus the hadronic projection of these sources are the useful output. The non-detection is consistent with later, more sensitive IceCube results, which is a good sign. The paper is honest about limitations: it explicitly notes TeV halos as an alternative leptonic explanation, and it does not pretend the hadronic assumption is proven.\n\nSoft spots, in order of severity. First, the pre-trial p-values without trial correction. Table 1 lists five tests; the most significant is 2%. That is a completeness gap in a conference proceeding, and the stress-test is right to flag it. The null conclusion is probably intact, but the formal significance statement is unquantified. Second, the paper omits systematic uncertainties and most likelihood implementation details—fine for a proceedings, but the numerical limits should be treated as preliminary. Third, the hadronic-origin assumption is structural for interpreting the limits; the authors acknowledge it, and the non-detection itself does not depend on it.\n\nThe citation pattern is sound: it builds on earlier IceCube point-source searches and cites the relevant HAWC catalog and Kappes et al. for the projection. No invented entities, no hidden free parameters beyond the fitted signal normalizations.\n\nWho is this for? Someone working on Galactic cosmic-ray accelerators or multimessenger source catalog cross-checks. It is a useful data point, not a breakthrough. The analysis is clear and honest; the main weakness is the missing trial correction, which is fixable in a journal version.\n\nMy recommendation: send it to peer review. It deserves referee time as a legitimate search result, and the collaboration should be encouraged to publish the trials-corrected version with systematics.","headline":"A solid, if thin, conference-proceedings null result: no IceCube neutrino excess from HAWC Galactic sources, with pre-trial p-values and an acknowledged hadronic assumption as the main caveats.","tokens_in":5840,"tokens_out":2133,"would_cite":true,"duration_ms":20877,"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":"None of the TeV-bright Galactic sources shows significant neutrino emission after eight years.","keywords":["neutrino astronomy","Galactic cosmic-ray accelerators","HAWC gamma-ray survey","stacked likelihood analysis","template morphological search","hadronic gamma-ray emission","muon-neutrino upper limits"],"falsifier":"Apply the same five likelihood tests to the next eight years of the same neutrino detector's exposure. If the 36.7-neutrino excess near 2HWC J1857+027 is real, the best-fit signal count should grow roughly linearly with exposure and the post-trial p-value should fall below $10^{-3}$; if the excess reverts to zero, it was a background fluctuation and the non-detection is confirmed. Independently, a gamma-ray spectral or multiwavelength demonstration that these sources' TeV emission is leptonic would invalidate the hadronic interpretation of the limits.","tokens_in":4756,"feed_emoji":"🔭","tokens_out":9750,"duration_ms":92312,"temperature":0.7,"pith_summary":"Galactic cosmic-ray accelerators should in principle reveal themselves by emitting neutrinos and gamma-rays together, because pion decay produces both. This paper takes a TeV gamma-ray map of the Galactic plane from the HAWC survey as the target list and searches eight years of muon-neutrino data from the Antarctic neutrino telescope for matching emission. Five hypotheses are tested: a stacked search over the catalog's non-pulsar-wind-nebula sources, and template searches weighted by the measured gamma-ray morphology over the northern Galactic plane, the Cygnus region, 2HWC J1908+06, and 2HWC J1857+027. The central result is that none of the five tests yields a statistically significant neutrino excess, so no claim of neutrino emission from these Galactic sources is made. The closest hint, a 36.7-neutrino excess around 2HWC J1857+027, has a pre-trial p-value of 2%, and the paper instead reports 90% confidence upper limits that, under a hadronic-origin assumption for the gamma-rays, constrain the hadronic component of the emission.","feed_headline":"Eight years of data show no neutrino signal from TeV gamma-ray sources","feed_subtitle":"The best candidate, a 36.7-neutrino excess near 2HWC J1857+027, reaches only a 2 percent pre-trial significance.","key_machinery":"The load-bearing mechanism is a stacking likelihood ratio in which the expected neutrino signal is weighted spatially by the gamma-ray morphology from the HAWC survey: point sources for the stacked search, and the measured flux at 7 TeV at every location for the template searches. A companion ingredient is the pion-decay conversion from the gamma-ray spectrum to an expected neutrino flux, which supplies the maximal hadronic reference curve against which each upper limit is judged. The likelihood framework is the same one used for pointed neutrino source searches, and it maximizes the number of signal neutrinos against the eight-year muon-neutrino track sample.","core_discovery":"The claim is that, after eight years of exposure, the neutrino sky shows no excess above background at the locations and morphologies where the HAWC survey sees TeV gamma-ray emission. The paper states that the observed signal excesses are not statistically significant for claiming evidence of neutrino emission associated with the gamma-ray emission measured by HAWC. In the absence of a detection, it sets 90% confidence upper limits on the muon-neutrino flux for each of the five hypotheses and compares those limits with the neutrino flux projected from the gamma-ray spectrum under the assumption that all detected high-energy gamma-rays are hadronic. The result is presented as marginal to expectations: for the northern-plane and stacked searches the limits begin to constrain the hadronic flux component, while for 2HWC J1908+06 the constraint is marginal and for 2HWC J1857+027 the fitted excess forces an upper limit too weak to constrain hadronic emission.","pith_inferences":["If TeV halos or other leptonic mechanisms explain most of the unidentified HAWC sources, the hadronic gamma-ray-to-neutrino projection used here overestimates the expected neutrino flux; in that case the limits say little about whether these sources accelerate cosmic rays, only that they do not emit hadronic gamma-rays at the assumed level.","The 36.7-neutrino excess at 2HWC J1857+027 is exactly the kind of marginal fluctuation that a longer exposure could confirm or rule out; doubling the exposure would be a direct test.","The same morphology-weighted template technique could be applied to diffuse Galactic plane emission or to future, deeper gamma-ray catalogs, where the integrated signal might exceed point-source sensitivity.","Weighting the templates by energy-dependent gamma-ray maps instead of a single 7 TeV flux map would sharpen the test, since the neutrino and gamma-ray effective areas respond differently with energy."],"forward_implications":["None of the five tested hypotheses can be claimed as a source of cosmic neutrinos, so the HAWC sources do not yet provide the smoking gun for hadronic Galactic cosmic-ray acceleration.","The 90% confidence upper limits quantitatively bound how much of the TeV gamma-ray flux from the stacked non-PWN sample and the northern-plane template can be hadronic at neutrino energies.","The Cygnus region receives the most stringent limit because the observation under-fluctuates, and the fitted-limit convention reduces its allowed neutrino flux by an additional 60%.","The excess around 2HWC J1857+027, though not significant, marks that region as the most promising target among those tested for continued observation.","Because pulsar wind nebulae were excluded from the stacked search, the result constrains sources whose TeV emission is not fully accounted for by leptonic PWN models."],"supporting_citations":[{"why":"Establishes that charged and neutral pion decays produce neutrinos and gamma-rays carrying about 5% and 10% of the primary cosmic-ray energy, the physical basis for expecting correlated emission.","marker":"[1]"},{"why":"Supplies the 2HWC catalog of 39 TeV sources; its non-PWN members form the stacked search sample and the updated sky map supplies the template morphologies.","marker":"[7]"},{"why":"Proposes the TeV-halo leptonic interpretation for sources without pulsar counterparts, which frames why the hadronic assumption is the weakest load-bearing premise.","marker":"[10]"},{"why":"Defines the eight-year muon-neutrino track data set from the Northern sky used in every search.","marker":"[11]"},{"why":"Provides the stacking likelihood methodology that both the point-source and template searches implement.","marker":"[12]"},{"why":"Documents the dedicated search for neutrinos from TeV pulsar wind nebulae, the reason PWN sources are excluded from the stacked sample.","marker":"[13]"},{"why":"Gives the prescription for converting the measured gamma-ray spectrum into a projected neutrino flux under hadronuclear interactions, used for the reference curves and limit comparison.","marker":"[15]"}],"fun_headline_variants":["No neutrino excess from HAWC's TeV sources after 8 years","IceCube finds no neutrinos from HAWC gamma-ray sources","Eight years of IceCube data show no neutrino–gamma correlation","HAWC sources silent in neutrinos: IceCube null result","Neutrino search at HAWC hotspots yields no signal"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The load-bearing premise, noted in the paper's Section 3 and assumed in Section 4, is that every gamma-ray used to build the search templates comes from pion decay; if the emission is leptonic instead, the projected neutrino fluxes do not apply and the upper limits must be reinterpreted.","fun_headline_variants_meta":{"raw":{"variants":["No neutrino excess from HAWC's TeV sources after 8 years","IceCube finds no neutrinos from HAWC gamma-ray sources","Eight years of IceCube data show no neutrino–gamma correlation","HAWC sources silent in neutrinos: IceCube null result","Neutrino search at HAWC hotspots yields no signal"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000164,"raw_usage":{"total_tokens":1210,"prompt_tokens":869,"completion_tokens":341,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":485,"completion_tokens_details":{"reasoning_tokens":254}},"tokens_in":485,"tokens_out":341,"duration_ms":3838,"temperature":1.0,"reasoning_tokens":254,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-14T11:36:04.568094+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Apply the same five likelihood tests to the next eight years of the same neutrino detector's exposure. If the 36.7-neutrino excess near 2HWC J1857+027 is real, the best-fit signal count should grow roughly linearly with exposure and the post-trial p-value should fall below $10^{-3}$; if the excess reverts to zero, it was a background fluctuation and the non-detection is confirmed. Independently, a gamma-ray spectral or multiwavelength demonstration that these sources' TeV emission is leptonic would invalidate the hadronic interpretation of the limits.","supporting_citations":[{"cited_title":"Halzen and A","cited_arxiv_id":null,"evidence_quote":"Establishes that charged and neutral pion decays produce neutrinos and gamma-rays carrying about 5% and 10% of the primary cosmic-ray energy, the physical basis for expecting correlated emission."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Supplies the 2HWC catalog of 39 TeV sources; its non-PWN members form the stacked search sample and the updated sky map supplies the template morphologies."},{"cited_title":"Linden and B","cited_arxiv_id":null,"evidence_quote":"Proposes the TeV-halo leptonic interpretation for sources without pulsar counterparts, which frames why the hadronic assumption is the weakest load-bearing premise."},{"cited_title":"Achterberg et al., Astropart","cited_arxiv_id":null,"evidence_quote":"Provides the stacking likelihood methodology that both the point-source and template searches implement."},{"cited_title":"Collaboration, Q","cited_arxiv_id":null,"evidence_quote":"Documents the dedicated search for neutrinos from TeV pulsar wind nebulae, the reason PWN sources are excluded from the stacked sample."},{"cited_title":"Kappes, J","cited_arxiv_id":null,"evidence_quote":"Gives the prescription for converting the measured gamma-ray spectrum into a projected neutrino flux under hadronuclear interactions, used for the reference curves and limit comparison."}],"review_version":1}