{"id":"6180ae95-5ebc-4ee6-b3f1-e92b2a3cd5a3","arxiv_id":"2501.08876","paper_version":1,"verdict":"UNVERDICTED","confidence":"HIGH","novelty_score":1.0,"correctness_risk":"low","formal_verification":"none","parameter_count":0,"one_line_summary":"A review of the current experimental status and future prospects for detecting the Diffuse Supernova Neutrino Background.","lead":"This paper is a summary of the search for the Diffuse Supernova Neutrino Background, the combined neutrino signal from all past core-collapse supernovae. It reviews the latest experimental limits and future sensitivity from Super-Kamiokande, JUNO, and Hyper-Kamiokande.","discovery_kind":"review","skeptic_critique":{"model":"deepseek-v4-flash","headline":"No significant objection identified: the review's central status claim is consistent with the cited experimental results, and the only caveat is the preliminary nature of the SK-Gd conference results.","rationale":"The reader's verdict is UNVERDICTED because the paper is a review with no new content, and the weakest assumption was that the cited interim results might be revised. I agree that reliance on preliminary SK-Gd proceedings is the main caveat, but I do not regard it as a load-bearing concern for the central claim: the claim is explicitly a snapshot of the field as of early 2025, and the quoted 2.3 sigma excess does not contradict the statement that the DSNB has not yet been detected. A 2.3 sigma excess is a fluctuation-level hint, not a discovery, so the abstract's wording is accurate. The paper does not attempt a novel derivation; Equation (1) is a schematic model and is not used to make a quantitative prediction. The figures and text are consistent with the cited literature. Therefore, no internal inconsistency, unsupported parametric claim, or fatal gap was identified. The only recommended action is to revisit the status summary when the SK-Gd results appear in a peer-reviewed publication, which is a normal updating practice rather than a reason to change the verdict.","tokens_in":4777,"tokens_out":4341,"duration_ms":45337,"concrete_test":"When the official Super-Kamiokande gadolinium-era DSNB publication becomes available, check the combined significance and the resulting flux upper limit against the values quoted in Section 3.1 and Figure 8; if the significance changes by more than ~0.5 sigma or the limit moves by more than ~20%, the status summary should be revised accordingly.","verdict_should_be":"UNCHANGED","load_bearing_attack":"This is a review article, not a new research claim. The abstract's central assertion is a status summary: the DSNB has not yet been detected, Super-Kamiokande provides the most sensitive search, and JUNO/Hyper-K will soon join. These claims are consistent with the described evidence. The quoted SK-Gd result is a ~2.3 sigma excess over background, which is explicitly below the conventional discovery threshold, so describing the DSNB as 'yet to be detected' is internally consistent. The paper's other experimental statements match the cited references at the level expected of a proceedings-style summary. No unsupported derivation or internal inconsistency was found in the modeling section or the new-physics discussion. The only genuine caveat is timeliness: several key SK-Gd results (refs 7, 8, 9, 11, 12) are Neutrino 2024 proceedings or preprints rather than final peer-reviewed publications. If those analyses are revised, the summary's numbers may need updating, but that is an updating issue, not a logical flaw in the review as of its submission date.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"This manuscript is a concise review of the current status of the Diffuse Supernova Neutrino Background (DSNB). It outlines the standard modeling ingredients (core-collapse supernova rate, neutrino emission spectra, stellar formation history, cosmology, and black-hole-forming fraction), summarizes experimental searches by Super-Kamiokande (including the 2024 Gd-loaded results with a reported ~2.3 sigma excess), JUNO, Hyper-Kamiokande, and LUX-ZEPLIN, and discusses three new-physics probes: non-radiative neutrino decay, dark-matter resonances, and sterile neutrinos/wave-packet effects. Its central claim, stated in the abstract, is that the DSNB has yet to be detected, that Super-K is currently the most sensitive experiment, and that JUNO and Hyper-K are set to join the search in the next few years.","tokens_in":5103,"tokens_out":4354,"duration_ms":44004,"significance":"As a review/proceedings contribution, the paper's value lies in providing a compact and current snapshot of the DSNB field, including very recent Super-K-Gd results from Neutrino 2024 and associated preprints. It usefully identifies the complementarity between JUNO and Super-K/Hyper-K in energy coverage and background rejection, and it highlights new-physics opportunities that exploit the long propagation distances of DSNB neutrinos. The review does not introduce new formalism or data, so its reliability depends on the external analyses it cites; I found no internal inconsistencies. In particular, the statement that the DSNB has not yet been detected is consistent with the reported ~2.3 sigma excess, which is below the conventional discovery threshold. The manuscript is transparent about ongoing sensitivity studies and does not overstate the evidence.","major_comments":[],"minor_comments":[{"comment":"Reference 10 is malformed as printed: \"Phys. Rev. Lett. 951, L27 (2023)\" is not a valid volume/page combination; please verify and correct the bibliographic entry.","section":"References"},{"comment":"The text reports \"approximately a 2.3 sigma rejection of a background-only hypothesis\" but does not clearly attribute this value to a specific figure or table in one of the cited Neutrino 2024 proceedings (refs 7, 8, 9, 11, or 12); adding an explicit pointer would make the claim easier to verify.","section":"Section 3.1"},{"comment":"The key Super-K results are drawn from conference proceedings and preprints (refs 7, 8, 9, 11, 12); the text should explicitly flag these numbers as preliminary and state that they may be updated after final journal publication.","section":"Section 3.1"},{"comment":"The sentence \"Notably, the Super-K and JUNO experiments will be running at the same time\" is awkward because Super-K is already in operation; consider rephrasing to indicate that JUNO's data-taking period will overlap with the ongoing Super-K running.","section":"Section 3.5"},{"comment":"Reference 8 has a formatting typo in the author name (\"Beauch\\^ene\" appears with a space before the comma); it should be \"A. Beauchêne\".","section":"References"},{"comment":"Some figure captions (e.g., Figures 1, 6, and 7) do not explicitly state whether the plots are reproduced or adapted from the cited works; for clarity and reproducibility, please use \"reproduced from\" or \"adapted from\" consistently in all captions.","section":"Figure captions"}],"recommendation":"minor_revision","confidential_remarks":"The manuscript relies heavily on the author's own conference contributions (refs 11 and 12) for the key Super-K-Gd results. This is not inherently problematic given the author's likely role in the experiment, but the editor may wish to confirm that those proceedings are publicly accessible and to be aware that the review's quantitative statements depend on preliminary results that could change before final peer-reviewed publication."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Hi [name],\n\nI've read Santos's DSNB review. It's a competent, up-to-date summary of where the diffuse supernova neutrino background search stands as of early 2025. No new data or derivation, but it does pull together the recent SK-Gd results (including the ~2.3σ excess) with JUNO, HK, and LZ in one place. The modeling section is a clean recap of the standard ingredients—star formation rate, spectral swapping, cosmological evolution—useful for someone entering the field.\n\nThe paper is honest about its limitations. It relies heavily on Neutrino 2024 proceedings and preprints for the most recent SK numbers, so those will need updating once the analyses are peer-reviewed. There's a typo in ref 10 (PRL volume number) and the LZ limit is quoted without context on its systematic uncertainties, but these are minor. The self-citations (refs 11, 12) are appropriate—they're prior analyses, not used to inflate anything. I agree with the stress test that the central status claim is internally consistent.\n\nWhat you get from this is a snapshot, not a breakthrough. The abstract's central claim—DSNB undetected, SK most sensitive, JUNO/HK coming—is consistent with the cited evidence. No circular reasoning, no overreach. The new-physics section is speculative but clearly labeled as such.\n\nWho's this for? Anyone wanting a quick orientation on DSNB searches, or a lecturer looking for a starting point. It doesn't advance the science. As a submission to a research journal, it would be a desk reject; as a review for a proceedings or a pedagogical journal, it deserves a careful referee to check the numbers against the primary sources. I'd say yes to peer review if the venue is appropriate.\n\nFor my own work, I wouldn't cite it as a primary source, but I might point students to it.\n\nBest,","headline":"A competent, current snapshot of DSNB searches—worth a referee's time only as a review, not as a novel contribution.","tokens_in":5432,"tokens_out":2258,"would_cite":false,"duration_ms":22254,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":["95.55.Vj","97.60.Bw"],"model":"deepseek-v4-flash","headline":"The diffuse supernova neutrino background has yet to be detected, and Super-Kamiokande's 2024 search is the most sensitive to date.","keywords":["diffuse supernova neutrino background","core-collapse supernovae","Super-Kamiokande","inverse beta decay","gadolinium loading","JUNO","Hyper-Kamiokande","neutrino non-radiative decay"],"falsifier":"Reanalyze the full SK-Gd dataset with updated systematics; if the 2.3 sigma excess drops below about 1 sigma, the claimed hint is refuted. Conversely, a greater-than-5-sigma excess in JUNO's first DSNB search in 2025–2026 would confirm the signal.","tokens_in":4601,"feed_emoji":"🌌","tokens_out":7250,"duration_ms":70661,"temperature":0.7,"pith_summary":"This review argues that the Diffuse Supernova Neutrino Background, the cumulative neutrino flux from all core-collapse supernovae since the beginning of the universe, has not yet been detected. It identifies Super-Kamiokande's 2024 results, which show a light excess and about a 2.3 sigma rejection of the background-only hypothesis, as the current frontier. The paper expects JUNO and Hyper-Kamiokande to reach competitive sensitivity in the next few years, with complementary energy coverage. A first detection would open a new window into star formation history, the fraction of supernovae forming black holes, and exotic physics such as neutrino decay and dark-matter interactions.","feed_headline":"Supernova neutrino background still undetected after 2024 search","feed_subtitle":"New Super-K hint at 2.3 sigma sets the stage for JUNO and Hyper-K to find it.","key_machinery":"The central object is the DSNB flux integral, \n$$\n\\frac{d\\Phi_{\\nu_\\$\\alpha$}}{dE} = \\int_{\\mathrm{CCSN}} \\$int_0^{{z_{\\max}}$} R_{\\mathrm{CCSN}}(z,M) \\frac{dF_{\\nu_\\$\\alpha$}(E(1+z),M)}{dM} \\left|\\frac{c\\,dt}{dz}\\right|\\,dz\\,dM,\n$$\nwhich packages the supernova rate, the emitted neutrino spectrum, and cosmological expansion. On the experimental side, detection relies on inverse $\\beta$ decay in water Cherenkov and liquid scintillator detectors, where the positron gives a prompt signal and the neutron gives a delayed capture signal, enhanced by gadolinium loading. The paper highlights machine-learning neutron identification and the multiple scattering goodness (MSG) variable, which separates single-cone IBD events from multi-gamma NCQE backgrounds and reduces NCQE events by up to an order of magnitude. This machinery determines the energy window and background budget of the search.","core_discovery":"The paper's central claim is that the DSNB remains undetected and that the most sensitive experimental search is Super-Kamiokande's combined 2024 analysis. In that analysis, an energy-binned fit shows a light excess over background-only predictions, corresponding to about a 2.3 sigma rejection of the background-only hypothesis across the DSNB models considered. The paper also argues that JUNO and Hyper-Kamiokande will soon join the search, with JUNO stronger at lower energies and Super-K/Hyper-K stronger at higher energies, making the experiments complementary across the full energy window. Beyond the standard astrophysical picture, the DSNB could probe neutrino non-radiative decay, dark-matter-neutrino resonances, and sterile-neutrino mixing scenarios.","pith_inferences":["A plausible reading is that the 2.3 sigma excess is the first statistical hint of the DSNB; combining SK-Gd and JUNO data over the next few years will either confirm it or reveal a shared background.","The DSNB flux difference between normal and inverted mass ordering under neutrino decay could be used as a complementary mass-ordering probe, beyond what the paper explicitly argues.","A detection would provide a nearly redshift-integrated census of core-collapse supernovae, so comparing it with optical supernova surveys could expose star formation hidden by dust."],"forward_implications":["If the 2.3 sigma excess is the first sign of the DSNB, a statistically robust detection is likely within the early running period of SK-Gd, JUNO, or Hyper-K.","The energy complementarity between JUNO at low energies and Super-K/Hyper-K at high energies means a combined analysis could cover the full search window.","A first DSNB detection would normalize the flux prediction and put direct constraints on the star formation history and the fraction of supernovae that form black holes.","Spectral features in the DSNB would probe non-radiative neutrino decay, dark-matter-neutrino resonances, and sterile-neutrino mixing scenarios."],"supporting_citations":[{"why":"The Super-K pure-water DSNB search supplies the baseline IBD analysis that the later gadolinium-era searches build on.","marker":"1"},{"why":"The Neutrino 2024 report on the combined SK-VI/VII energy-binned spectrum is the source of the observed light excess.","marker":"7"},{"why":"This Neutrino 2024 spectral fit is one of the analyses combined to derive the 2.3 sigma background-only rejection.","marker":"8"},{"why":"This Neutrino 2024 spectral fit contributes the SK-I/II/III and combined-phase comparison shown in the results.","marker":"9"},{"why":"The first Super-K gadolinium-era search establishes the energy-binned analysis method used in the 2024 update.","marker":"10"},{"why":"This Neutrino 2024 report provides the SK-Gd expected limits and the combined SK phases behind the headline sensitivity.","marker":"11"},{"why":"This work introduces the multiple-scattering-goodness background reduction that shapes the current DSNB search window.","marker":"12"},{"why":"The JUNO DSNB search plan supplies the detector sensitivity and the comparison plot for the outlook.","marker":"14"}],"fun_headline_variants":["Supernova neutrino background undetected despite 2.3 sigma hint","DSNB search: no detection, but Super-K hints at 2.3 sigma","Super-K's hint keeps supernova neutrino hunt open, JUNO and Hyper-K next","Cosmic supernova neutrinos: still elusive, but new detectors on the way","2.3 sigma hint keeps DSNB search alive as new detectors join"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The summary leans on preliminary 2024 Super-K results and background estimates from conference proceedings; if those numbers shift, the status of the DSNB search shifts with them.","fun_headline_variants_meta":{"raw":{"variants":["Supernova neutrino background undetected despite 2.3 sigma hint","DSNB search: no detection, but Super-K hints at 2.3 sigma","Super-K's hint keeps supernova neutrino hunt open, JUNO and Hyper-K next","Cosmic supernova neutrinos: still elusive, but new detectors on the way","2.3 sigma hint keeps DSNB search alive as new detectors join"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000757,"raw_usage":{"total_tokens":3295,"prompt_tokens":809,"completion_tokens":2486,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":425,"completion_tokens_details":{"reasoning_tokens":2380}},"tokens_in":425,"tokens_out":2486,"duration_ms":18987,"temperature":1.0,"reasoning_tokens":2380,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-10T20:14:14.851325+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Reanalyze the full SK-Gd dataset with updated systematics; if the 2.3 sigma excess drops below about 1 sigma, the claimed hint is refuted. Conversely, a greater-than-5-sigma excess in JUNO's first DSNB search in 2025–2026 would confirm the signal.","supporting_citations":[{"cited_title":"Abe et al , Phys","cited_arxiv_id":null,"evidence_quote":"The Super-K pure-water DSNB search supplies the baseline IBD analysis that the later gadolinium-era searches build on."},{"cited_title":"Harada, Proceedings of Neutrino 2024 (2024)","cited_arxiv_id":null,"evidence_quote":"The Neutrino 2024 report on the combined SK-VI/VII energy-binned spectrum is the source of the observed light excess."},{"cited_title":"Beauchˆ ene,Proceedings of Neutrino 2024 (2024)","cited_arxiv_id":null,"evidence_quote":"This Neutrino 2024 spectral fit is one of the analyses combined to derive the 2.3 sigma background-only rejection."},{"cited_title":"Rogly, Proceedings of Neutrino 2024 (2024)","cited_arxiv_id":null,"evidence_quote":"This Neutrino 2024 spectral fit contributes the SK-I/II/III and combined-phase comparison shown in the results."},{"cited_title":"Harada et al , Phys","cited_arxiv_id":null,"evidence_quote":"The first Super-K gadolinium-era search establishes the energy-binned analysis method used in the 2024 update."},{"cited_title":"Santos et al , Proceedings of Neutrino 2024 (2024)","cited_arxiv_id":null,"evidence_quote":"This Neutrino 2024 report provides the SK-Gd expected limits and the combined SK phases behind the headline sensitivity."},{"cited_title":"Abusleme, JCAP 10, 033 (2022)","cited_arxiv_id":null,"evidence_quote":"The JUNO DSNB search plan supplies the detector sensitivity and the comparison plot for the outlook."}],"review_version":1}