{"id":"61cf5428-4ae1-4f3d-8810-f4daa805bdcb","arxiv_id":"2412.07861","paper_version":3,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":6,"one_line_summary":"Sub-GeV dark matter scattering off protons in blazar jets can produce the IceCube neutrino from TXS 0506+056 while evading current dark matter constraints.","lead":"Blazar jets are expected to emit too few neutrinos to explain IceCube's 2017 detection from TXS 0506+056. This paper adds collisions between jet protons and dark matter clustered around the blazar's black hole, and shows the extra neutrinos can match the observation with dark matter parameters that remain allowed by other searches.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"BMCI spike requires an annihilation cross-section below ~3e-30 (mDM/GeV) cm^3/s, far below a thermal relic; an annihilation-plateau-corrected column raises σ_DIS and may push the required parameters outside the claimed allowed region.","rationale":"The paper is a carefully executed existence proof: it adds DM-proton DIS to existing lepto-hadronic jet models and shows that a sub-GeV vector-mediated DM model can reproduce the TXS 0506+056 neutrino while passing current experimental bounds. The calculation chain in Eq. (2) and Appendix B is transparent, and the MadGraph-vs-analytic cross-section check in Fig. 3 is genuine supporting evidence. The weakest point is not the particle physics but the astrophysical input that linearly controls the signal: the assumed DM spike column density. I agree with the reader that this is the load-bearing uncertainty, but I would sharpen it into a specific internal-consistency problem. The BMCI benchmark, which most naturally yields the claimed flux, requires an annihilation cross-section orders of magnitude below a simple thermal relic, and the paper does not recompute the flux using the annihilation plateau that such a relic would create. This makes the statement 'allowed by all existing searches' incomplete in an important sense: being allowed by direct-detection limits is not the same as being self-consistent with a simple cosmological history for the same DM candidate. The proposed concrete test would settle whether an annihilation-corrected column still keeps the required σ_NR below direct-detection bounds. Because the paper already frames the result as conditional and acknowledges the uncertainty in rmin, the reader's CONDITIONAL verdict remains appropriate; however, the condition should be stated as 'subject to a self-consistent DM spike and cosmological production mechanism', not merely 'subject to rmin'.","tokens_in":17906,"tokens_out":22061,"duration_ms":226606,"concrete_test":"Fix the paper's N and Rsp, take a thermal s-wave cross-section ⟨σann vrel⟩ = 3×10^-26 cm^3/s and tBH = 10^9 yr, compute rann from Eq. (A2) and the modified column Σ = ρ_core rann + ∫_{rann}^{Rsp} ρ_spike dr; insert this Σ into Eq. (2) and re-derive the σ_NR needed to match IC-170922A for mDM = 30 MeV and 1 MeV. Plot those points against the direct-detection bounds shown in Fig. 2. If the points lie below the bounds, the concern is resolved; if they fall inside the excluded grey regions, the central claim currently rests on a non-self-consistent spike benchmark.","verdict_should_be":"UNCHANGED","load_bearing_attack":"Equation (2) makes the predicted neutrino flux proportional to the DM column density Σ_spike_DM. The high-flux benchmark BMCI (rmin = 10^2 R_S, main text) is not self-consistent for DM with a non-negligible s-wave annihilation cross-section: Appendix A requires rann < rmin, i.e. ⟨σann vrel⟩ ≲ 3.1×10^-30 (mDM/GeV) cm^3/s for BMCI. For mDM = 30 MeV this is about 9×10^-32 cm^3/s, roughly five orders of magnitude below the canonical thermal value ~3×10^-26 cm^3/s. For a thermal (or even a much more weakly annihilating) candidate, annihilations create a core with rann > rmin, and the column density is set by ρ_core rann plus the surviving outer spike, not by the full GS profile. The resulting column lies between the BMCI and BMCII values or below, so the required σ_NR rises correspondingly. The paper uses the two rmin choices as 'a way to effectively account also for astrophysical or DM softenings', but this does not replace a calculation with the annihilation-modified profile: the geometric cut changes the integration lower limit, whereas annihilations change the profile shape. Since the central claim is that the needed cross-section is allowed by direct detection, this upward shift in σ_NR is the decisive check. If the shift moves the TXS line into the SENSEI/CRESST/XENONnT exclusion regions, the explanation survives only for non-thermal (e.g. freeze-in) DM with suppressed annihilation, and the paper should state that condition explicitly.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper proposes that the IceCube 2017 neutrino from TXS 0506+056 was produced by deep inelastic scattering between protons in the blazar jet and sub-GeV dark matter accumulated in a spike around the central supermassive black hole. Starting from existing lepto-hadronic jet models for TXS 0506+056 and AP Librae, the authors compute the neutrino flux from DM-proton DIS, normalize it to the IceCube event, and then compare the required DM-proton cross section with direct-detection, LEP, and BBN constraints. They find an allowed region for a vector-mediator model with m_DM in the sub-GeV range and claim that the mechanism is robust across two jet models for TXS 0506+056 and also viable for AP Librae.","tokens_in":18269,"tokens_out":6652,"duration_ms":64007,"significance":"If the claimed parameter region survives closer scrutiny, the paper would open a genuinely new and falsifiable channel for non-gravitational dark matter detection: high-energy neutrinos from blazar jets scattering on DM spikes. The manuscript has real strengths. The flux formula in Eq. (2) is transparent; the analytic DIS cross section in Eq. (B1) is checked against MadGraph5 at the 20% level; the calculation is repeated for two independent TXS jet models and one additional blazar; and the required couplings are compared with a broad set of laboratory, direct-detection, and cosmological bounds. The predicted spectral shape is distinct from standard jet neutrinos, so future multi-neutrino associations can test the proposal. The main weakness is not the collider or direct-detection side but the input dark matter column density, which is admittedly 'somewhat arbitrary' and controls the flux linearly.","major_comments":[{"comment":"The high-flux benchmark BMCI is not self-consistent for a dark matter candidate with a thermal s-wave annihilation cross section. Requiring r_ann < r_min, as stated after Eq. (1), imposes <sigma_ann v_rel> <~ 3.1 x 10^-30 (m_DM/GeV) cm^3/s for r_min = 10^2 R_S (Eq. (A3)); for m_DM = 30 MeV this is about 9 x 10^-32 cm^3/s, roughly five orders of magnitude below the canonical thermal value ~3 x 10^-26 cm^3/s. For a thermal candidate the annihilation plateau has r_ann > r_min, so the column density in Eq. (1) should be computed from the annihilation-modified profile (a core contribution rho_core r_ann plus the surviving outer spike) rather than from a geometric cutoff of the unmodified Gondolo-Silk profile. Since Eq. (2) makes the predicted flux linear in Sigma_spike_DM, the resulting upward shift in the required sigma_NR is the decisive check of the 'allowed by all searches' claim. I ask the authors to perform the calculation with the annihilation-modified profile, or alternatively to state explicitly and consistently that the BMCI claim applies only to non-thermal (e.g. freeze-in) dark matter with strongly suppressed annihilation.","section":"Sec. 3 and Appendix A, Eq. (A3)"},{"comment":"The normalization of the DM spike is not derived from observations: the paper fixes R_sp = R_star = 10^6 R_S and chooses N so that dark matter inside R_star is only O(10%) of M_BH, calling the normalization 'somewhat arbitrary.' Because the predicted neutrino flux is proportional to the column density, the central conclusion that the required dark matter parameters are allowed by all existing searches inherits the full uncertainty of this choice. The two benchmarks r_min = 10^2 R_S and r_min = 10^4 R_S bracket the geometric integration limit, but they do not cover profile-shape modifications induced by annihilations, mergers, or stellar heating, which change rho_DM(r) rather than only the lower integration limit. I recommend presenting the required sigma_NR as a function of Sigma_spike_DM (or of the integrated dark matter mass along the jet path), so that the reader can see how much spike erosion is tolerated before the model is excluded by direct-detection or BBN bounds.","section":"Sec. 3, Eq. (1)"}],"minor_comments":[{"comment":"The threshold values 1.4 x 10^-25 and 3.1 x 10^-30 cm^3 s^-1 (m_DM/GeV) should be explicitly assigned to r_min = 10^4 R_S (BMCII) and r_min = 10^2 R_S (BMCI); the current parenthetical order is easy to misread, and the same ambiguity appears in Appendix A.","section":"After Eq. (1)"},{"comment":"The monochromatic-jet benchmark would be more reproducible if the text stated whether the same angular cone (1 - 10^-5 <= cos theta <= 1) and the same MadGraph/Pythia event-selection settings were used as in the main flux calculation.","section":"Fig. 4"},{"comment":"Reference [96] is a conference contribution without a stable archival identifier; please update it to the published KM3NeT paper or to a stable arXiv entry once available.","section":"Reference [96]"},{"comment":"The phrase 'call out loud' is nonstandard; consider 'call for' or 'highlight.'","section":"Summary and discussion"}],"recommendation":"major_revision","confidential_remarks":"The paper is honest about its main astrophysical uncertainty and does not hide the r_min dependence of the result. My recommendation of major revision is intended to require a direct treatment of the annihilation-modified spike: the current BMCI benchmark is not a valid thermal-dark-matter scenario, and the paper's central 'allowed by all searches' claim depends on this point. The title and abstract may overstate the discovery aspect, but that is a framing issue rather than a technical error."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"This paper is a real addition to the blazar-DM literature. It is the first to compute neutrinos from deep inelastic DM–proton scatterings inside the jet, and it does that carefully: the flux formula is clean, the analytic DIS cross section matches MadGraph at the ~20% level, and the results are checked against two independent TXS jet fits plus AP Librae. The constraint figures include direct detection, LEP, BBN, and both vector and scalar mediators, with honest caveats about where the limits depend on the UV completion. That is the right way to present an existence proof.\n\nThe soft spot is exactly where the reader's report puts it: the overall normalization is the DM column density Σ_spike, and that column is set by hand. Setting Rsp to the radius of influence and fixing the normalization so that DM inside R⋆ is only ~10% of M_BH is defensible and conservative relative to earlier work, but the choice of rmin = 10^2 R_S (BMCI) is doing a lot of work. The stress-test note is correct: for BMCI, the paper's own Appendix A requires ⟨σann v⟩ ≲ 3.1×10^-30 (mDM/GeV) cm^3/s to keep the annihilation core inside rmin. For a 30 MeV candidate that is about five orders of magnitude below the canonical thermal value. A thermal or even much more weakly annihilating candidate would flatten the central profile, reducing the column and pushing the required σ_NR up—likely into SENSEI/CRESST/XENONnT territory. The authors use the two rmin benchmarks as a proxy for \"softenings\", but a geometric integration cutoff is not the same as a self-consistent annihilation-modified density profile. They don't compute the latter. That is a genuine gap, not a manufactured one.\n\nIt does not sink the paper. For freeze-in or asymmetric DM with strongly suppressed annihilation, BMCI is fine, and the mechanism is testable through future blazar neutrinos and DM searches. But the summary's claim to explain TXS with parameters \"allowed by all searches\" should be qualified: it holds for DM with a very small annihilation cross section, and the paper should state that. The abstract overreaches a bit.\n\nI'd send this to a serious referee. The mechanism is novel, the computation is reproducible in principle from the appendix detail (though no code is released), and the astrophysical uncertainty is clearly separated from the particle physics input. The referee should be asked to check the annihilation-core calculation, or to require the authors to state the condition more prominently.","headline":"A novel, carefully executed mechanism for blazar neutrinos worth engaging, but the headline claim rests on a spike column density that DM annihilations can erode.","tokens_in":18870,"tokens_out":2608,"would_cite":true,"duration_ms":24670,"reading_group":"yes","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 proposes that the 2017 IceCube neutrino from TXS 0506+056 came from deep inelastic collisions between protons in the blazar's jet and sub-GeV dark matter in a spike around its black hole, making it a candidate first…","keywords":["dark matter","blazar jets","neutrino astronomy","IceCube","TXS 0506+056","deep inelastic scattering","dark matter spikes","sub-GeV dark matter"],"falsifier":"Determine the dark matter column density inside $10^2\\,R_S$ of the TXS 0506+056 black hole from independent astrophysical probes such as stellar kinematics, pulsar timing, or gravitational lensing; if it is more than an order of magnitude below $6.9\\times10^{28}\\,\\mathrm{GeV\\,cm^{-2}}$, the predicted neutrino signal cannot match the 2017 IceCube event without cross sections that direct-detection or big bang nucleosynthesis bounds already exclude.","tokens_in":17655,"feed_emoji":"🌌","tokens_out":9771,"duration_ms":82281,"temperature":0.7,"pith_summary":"Lepto-hadronic models of blazar jets—those that accelerate both electrons and protons—can reproduce the photon spectra of TXS 0506+056 but predict a neutrino flux roughly two orders of magnitude below what IceCube observed in 2017. This paper proposes that the missing neutrinos come from deep inelastic scatterings between protons in the jet and sub-GeV dark matter packed into a spike around the central black hole. Using two different jet fits for TXS 0506+056 and one for the blazar AP Librae, it shows the same dark matter-proton interactions raise the predicted neutrino flux to the observed level while keeping dark matter parameters inside all laboratory, direct-detection, and early-universe bounds. If the proposal is right, the 2017 blazar neutrino would be the first non-gravitational dark matter signature ever seen.","feed_headline":"Dark matter hits in the jet may explain IceCube's 2017 blazar neutrino","feed_subtitle":"Jet models underproduce the 2017 blazar neutrino by ~100x; dark-matter scattering fills the gap within all limits.","key_machinery":"The load-bearing quantity is the line-of-sight dark matter column density through the spike, $\\Sigma^{\\rm spike}_{\\mathrm{DM}} = \\int_{r_{\\min}}^{R_{\\rm sp}}\\rho_{\\rm DM}(r')\\,dr'$, where $\\rho_{\\rm DM}$ follows a Gondolo-Silk spike with $\\rho_{\\rm DM}\\propto r^{-7/3}$ normalized so dark matter inside $R_{\\star}\\simeq 10^6 R_S$ amounts to about 10% of the black hole mass. The predicted neutrino flux is linearly proportional to this single integral, so its normalization controls the entire result. The particle-physics engine is a deep inelastic scattering cross section for a vector mediator coupling dark matter to first-generation quarks, folded with parton distribution functions and a Monte Carlo showering chain to obtain the number of neutrinos produced per collision as a function of energy.","core_discovery":"The central claim is that the PeV neutrino IceCube-170922A from TXS 0506+056, which standard lepto-hadronic jet models underpredict by about two orders of magnitude, can be explained by deep inelastic scattering of jet protons off a spike of sub-GeV dark matter around the black hole. The predicted flux is proportional to the line-of-sight column density of the spike, and with a fiducial spike starting at $10^2\\,R_S$ the required non-relativistic dark matter-proton cross sections lie between roughly $10^{-45}$ and $10^{-35}\\,\\mathrm{cm}^2$ for dark matter masses from $10^{-5}$ to $1\\,\\mathrm{GeV}$, values that evade every current bound from direct detection, LEP searches, and big bang nucleosynthesis. The same mechanism also raises the neutrino flux from AP Librae, showing TXS 0506+056 is not an isolated case, and the conclusion survives the choice between the two fitted jet models for TXS 0506+056. The paper frames the result as the possibility that the first neutrino detected from a blazar is the first sign of a non-gravitational dark matter interaction.","pith_inferences":["Inference: because the dark matter column density is steady, the same mechanism would also explain the 2014/15 TXS 0506+056 neutrino flare without requiring a simultaneous photon flare, giving a second, independent observational handle.","Inference: stacking many blazars and looking for the characteristic low-energy turnover of dark matter-proton deep inelastic scattering could measure the dark matter mass, since the flux shape depends on $m_{\\mathrm{DM}}$ only at low $E_\\nu$.","Inference: if the scenario is right, proton jets that are not aimed at Earth would still scatter off the same dark matter spike, producing a population of upscattered dark matter particles and isotropic lower-energy neutrinos that existing neutrino telescopes could search for."],"forward_implications":["If the proposal is correct, the 2017 IceCube event from TXS 0506+056 is a candidate first non-gravitational detection of dark matter rather than a purely hadronic jet neutrino.","The mechanism generically predicts that dark matter-proton scattering dominates the neutrino flux from other blazars, not just TXS 0506+056, so stacking analyses of blazar neutrinos become dark matter searches.","The energy shape of the dark matter-induced flux depends on the dark matter mass at low neutrino energies, so future coincident blazar-neutrino observations can discriminate this mechanism from conventional jet emission.","The dark matter parameters needed are within the reach of current and next-generation direct detection and low-energy collider searches, meaning the scenario can be confirmed or refuted by non-astrophysical experiments.","Including dark matter-proton scattering in jet fits could simultaneously relieve the too-large proton luminosities that plague lepto-hadronic models."],"supporting_citations":[{"why":"Supplies the Gondolo-Silk spike profile used to compute the dark matter column density that normalizes the signal.","marker":"[5]"},{"why":"Provides the line-of-sight integral formalism and the proton-flux normalization on which Eq. (2) is built.","marker":"[8]"},{"why":"Gives the TXS 0506+056 lepto-hadronic jet fit with the largest neutrino flux, the main benchmark the dark matter mechanism must exceed.","marker":"[20]"},{"why":"Supplies the alternative TXS 0506+056 jet fit used to show the result is not specific to one jet model.","marker":"[18, 19]"},{"why":"Reports the 2017 IceCube neutrino event and its coincident multiwavelength flare, the central observation the paper aims to explain.","marker":"[4]"},{"why":"Reports the 2014/15 neutrino flare from TXS 0506+056, a second IceCube observation the mechanism can address.","marker":"[24]"},{"why":"Supplies the 324-blazar lepto-hadronic modeling used to select AP Librae as a representative second source.","marker":"[49]"},{"why":"Gives the IceCube stacking upper limits that the predicted AP Librae neutrino flux must respect.","marker":"[50]"},{"why":"Computes parton-level deep inelastic scattering events between dark matter and protons for the neutrino yield calculation.","marker":"[81]"},{"why":"Simulates showering, hadronization, and decays that convert the scattering events into final-state neutrino spectra.","marker":"[82]"}],"fun_headline_variants":["Dark matter scattering in jets explains IceCube's blazar neutrino","Jet protons hitting dark matter spike produce the 2017 blazar neutrino","Sub-GeV dark matter spike boosts blazar neutrino flux to IceCube sensitivity","Dark matter in blazar jets fills the missing neutrino flux","IceCube's first blazar neutrino may come from dark matter interactions"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The load-bearing premise is that a dense cusp of dark matter around the black hole contains as much mass as the calculation assumes and begins at the assumed inner radius; if the cusp is eroded, starts farther out, or is lighter, the required interaction strength rises above what experiments currently allow.","fun_headline_variants_meta":{"raw":{"variants":["Dark matter scattering in jets explains IceCube's blazar neutrino","Jet protons hitting dark matter spike produce the 2017 blazar neutrino","Sub-GeV dark matter spike boosts blazar neutrino flux to IceCube sensitivity","Dark matter in blazar jets fills the missing neutrino flux","IceCube's first blazar neutrino may come from dark matter interactions"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000319,"raw_usage":{"total_tokens":1807,"prompt_tokens":958,"completion_tokens":849,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":574,"completion_tokens_details":{"reasoning_tokens":758}},"tokens_in":574,"tokens_out":849,"duration_ms":7168,"temperature":1.0,"reasoning_tokens":758,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-11T18:30:04.207144+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Determine the dark matter column density inside $10^2\\,R_S$ of the TXS 0506+056 black hole from independent astrophysical probes such as stellar kinematics, pulsar timing, or gravitational lensing; if it is more than an order of magnitude below $6.9\\times10^{28}\\,\\mathrm{GeV\\,cm^{-2}}$, the predicted neutrino signal cannot match the 2017 IceCube event without cross sections that direct-detection or big bang nucleosynthesis bounds already exclude.","supporting_citations":[],"review_version":1}