{"id":"84777879-31a8-4956-90a0-c85230d236de","arxiv_id":"2501.14835","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":3.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":0,"one_line_summary":"DUNE and T2HK could constrain long-range neutrino-matter interactions from 14 U(1)' symmetries to the 10^-14 to 10^-13 eV level, potentially identifying the responsible symmetry.","lead":"This physics analysis forecasts how well the next large neutrino experiments DUNE and T2HK could detect or rule out new long-range forces between neutrinos and ordinary matter. It covers 14 possible new symmetries and finds the experiments should reach potentials near 10^-14 to 10^-13 eV, enough to outperform many existing constraints for very light mediators.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The abstract's 'identify the new U(1)' claim is unsupported: the shown Δχ² curves are per-texture upper limits, not cross-symmetry discrimination tests.","rationale":"The paper's central claim has two parts: DUNE and T2HK can constrain VLRI to roughly 10^-14 to 10^-13 eV, and in some favorable cases they may identify the U(1)' symmetry responsible for it. The first part is supported by the projected Δχ² curves, modulo the statistical assumptions that the Reader already flagged as the weakest load-bearing premise. The second part, however, is an overreach relative to the evidence shown: an upper limit on each texture is not a separation between textures. Without a cross-symmetry model-discrimination test, 'identify' is not established. This is a logical gap in the presentation, not a speculation about the underlying JHEP analysis; if the full analysis contains such tests, the proceedings should state that and summarize the result. This keeps the verdict CONDITIONAL rather than ACCEPT: the standalone submission should either surface the identifiability analysis or temper the abstract's identification claim. I partially agree with the Reader's weakest-assumption assessment: the statistical model is indeed the main quantitative reliability issue, but the more acute and internal issue is the unsupported identification claim in the abstract.","tokens_in":5966,"tokens_out":11921,"duration_ms":122702,"concrete_test":"Run a pseudo-experiment campaign with the full Ref [1] simulation: for each of the 14 U(1)' charge assignments, inject a signal at the claimed 2σ reach (e.g., VLRI = 5×10^-14 eV for an ee-entry texture), then fit all 14 textures under the same nuisance treatment and compute the pairwise Δχ². Report the fraction of pseudo-experiments where the injected symmetry is recovered at ≥2σ, and a confusion matrix between textures. If the recovery fraction is not well above chance in the claimed 'favorable cases,' the abstract's identification claim should be softened.","verdict_should_be":"UNCHANGED","load_bearing_attack":"Section III and Figs. 1-3 report only single-texture constraints: for each candidate VLRI texture, the test statistic is a Poissonian Δχ² against the null hypothesis, minimized over θ23, δCP, and mass ordering. These curves bound each texture individually and cannot tell whether an observed signal would favor one U(1)' charge assignment over another. The abstract nevertheless promises that DUNE and T2HK 'may identify the new U(1)' symmetry responsible for it' in some favorable cases. Identification requires a model-selection step: e.g., comparing diag(V,0,0) vs diag(0,V,0) vs diag(0,V,-V) and showing the true texture is recovered at a useful confidence after marginalizing over the oscillation parameters. No such likelihood-ratio or confusion-matrix analysis appears in this text, and the degeneracies the authors themselves mention — between VLRI and θ23, δCP, and the mass ordering, in Sec. III — make it plausible that different U(1)' charges produce overlapping signatures. The quantitative limit-setting results may be valid, but the strongest 'identify' claim is not derivable from the material presented. It should either be removed from the abstract or accompanied by an identifiability analysis.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"This proceedings contribution summarizes sensitivity forecasts for long-range neutrino interactions (LRI) at DUNE and T2HK, based on the authors' earlier detailed study in JHEP 09 (2024) 055. The paper considers 14 U(1)' gauge symmetries built from combinations of lepton and baryon numbers, each inducing a flavor-dependent long-range matter potential VLRI. Using a Poissonian chi-square statistic that is marginalized over the uncertain oscillation parameters θ23, δCP, and the mass ordering, the authors present projected upper limits on VLRI for each texture (Fig. 2) and convert them to constraints on the effective coupling G' vs mediator mass m_Z' (Fig. 3). The central quantitative claim is that the combined DUNE+T2HK dataset can constrain VLRI at roughly 10^-14 to 10^-13 eV for all candidate symmetries, with the tightest limits in channels that primarily affect ν_μ→ν_μ disappearance. The abstract additionally claims that the experiments may 'identify the new U(1)' symmetry' in favorable cases.","tokens_in":6091,"tokens_out":5386,"duration_ms":47935,"significance":"If the forecasts are reliable, the paper provides a useful systematic survey of long-range neutrino interaction models and identifies the oscillation channels that give the strongest sensitivity. The observation that a long-range potential comparable to the standard oscillation Hamiltonian can be probed is well taken, and the comprehensive treatment of U(1)' symmetries is a strength. The paper also clearly points to the underlying JHEP publication for the full statistical machinery, which is appropriate for a proceedings. However, the abstract's identification claim is not supported by the per-texture limit-setting analysis, and the conversion to coupling limits in Fig. 3 is not documented in this manuscript. These issues affect the strength of the advertised conclusions.","major_comments":[{"comment":"The abstract and conclusions claim that DUNE and T2HK 'may identify the new U(1)' symmetry' in favorable cases, but the analysis in Section III only computes, for each candidate texture, a Poissonian Delta-chi^2 against the null hypothesis of standard oscillations. No model-selection test is presented that compares different U(1)' charge assignments after marginalizing over theta23, deltaCP, and the mass ordering. In fact, the degeneracies acknowledged after Fig. 1—between VLRI and theta23, deltaCP, and the mass ordering—make it plausible that different textures produce overlapping signatures. The identification claim is therefore not derivable from the material shown. Please either remove the claim from the abstract and conclusions or add an explicit identifiability/confusion-matrix analysis.","section":"Abstract; Section IV"},{"comment":"The conversion from the VLRI limits of Fig. 2 to the effective-coupling limits G' vs m_Z' shown in Fig. 3 is not documented in this manuscript. The caption states that the limits are 'converted' from the VLRI limits, and the text refers to Ref. [1] for details, but the reader cannot reproduce or assess the result without knowing the definition of G', the relation between G' and VLRI (including the U(1)' charges of matter fermions), and the celestial source densities used. Since the claim that DUNE and T2HK may outperform existing limits for light mediators rests on this conversion, please include at least the defining equation and a brief description of the source model.","section":"Section III, Fig. 3"},{"comment":"The projected sensitivities depend entirely on the statistical treatment defined in Ref. [1], including the Poissonian chi-square, nuisance parameters for detector systematics, backgrounds, and efficiencies. None of these are described here, yet the central quantitative claim that 'in all cases' DUNE and T2HK can constrain VLRI at the level of the standard-oscillation terms presupposes that the assumed systematic uncertainties are realistic. Please state explicitly which systematic errors are included and how they are implemented, or provide a more detailed pointer to the exact sections of Ref. [1], so that a reader cannot inadvertently over-interpret the projected limits.","section":"Section III"}],"minor_comments":[{"comment":"There is a typo in the workshop name: 'W orkshop' should be 'Workshop'.","section":"Header"},{"comment":"Many numbers have missing spaces, e.g., '10 −10 eV' and '10 −35 − 10−10 eV' in the Introduction; these should be formatted consistently as '10^{-10} eV' etc.","section":"Throughout"},{"comment":"The phrase 'For the first time, we explore a plethora of U(1)' symmetries' is misleading because the same authors have already explored these symmetries in Ref. [1], on which this contribution is based. Please rephrase to avoid a novelty claim that this proceedings does not carry.","section":"Introduction"},{"comment":"The arrows in the caption, e.g., 'E = 18 GeV →' and '≤ 0.2 (Hvac)ττ', are unclear. Please explain in the caption what these annotations mean, or remove them if they are only decorative.","section":"Fig. 1 caption"}],"recommendation":"major_revision","confidential_remarks":"This is a proceedings contribution summarizing a detailed JHEP paper. The main quantitative results appear valid if the underlying analysis is sound, but the abstract overreaches with the 'identify the U(1)' symmetry' claim, which the presented per-texture limit-setting analysis cannot support. The conversion to coupling limits in Fig. 3 also needs at least a defining equation to be self-contained. I recommend major revision to address these issues, after which the paper could be suitable for publication as a proceedings."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Quick take: this is a conference proceedings that restates the authors' own JHEP 09 (2024) 055 analysis. If you want the actual results, read Ref [1]; this text gives the summary figures and the 14-symmetry catalog but no statistical machinery, no detector simulation details, and no source-density modeling. The one new claim that is not in the original paper is in the abstract: DUNE and T2HK 'may identify the new U(1)' symmetry.' That claim is unsupported by anything in this text. The test statistics shown are upper limits on each VLRI texture separately, not a model-selection comparison between textures. The authors themselves mention degeneracies with θ23, δCP, and mass ordering in Section III, which make cross-symmetry identification even less obvious. Unless there is a confusion-matrix or likelihood-ratio analysis somewhere, the 'identify' wording should be cut.\n\nWhat the paper does well: it is honest about being a summary. It states in the introduction and again in the conclusions that it is based on Ref [1]. The Figures 1 and 2 give a compact view of the projected VLRI constraints for all 14 charge assignments, and Figure 3 translates them to coupling limits. For a reader who wants the broad-brush numbers without wading through JHEP, this is a useful digest.\n\nThe soft spots are exactly what the reader notes. The central quantitative results — the 10^-14 to 10^-13 eV sensitivity band and the per-symmetry limits — are not derivable from this text alone. They live in Ref [1]. The conversion from VLRI limits to coupling limits in Figure 3 is not documented here. No code or data are included. For a proceedings that is normal, but the arXiv posting is a standalone document; a reader landing here without Ref [1] cannot check the numbers. The circularity concern is minor: these are forecasts against the standard-oscillation null hypothesis, not fits to real data, so the constraints are not forced by construction. The heavy reliance on the authors' own earlier paper is a citation-pattern fact, not a flaw.\n\nBottom line: this is a proceedings summary, not a new result. If it is meant as a citable paper, the abstract overclaim must be fixed. If it is just a NuFact contribution, it is acceptable. As a regular journal submission, I would not send it to a full referee because it is not self-contained and adds nothing beyond Ref [1]. The underlying JHEP paper is the thing to cite.","headline":"A useful proceedings digest of the authors' JHEP long-range neutrino interaction forecasts, but the abstract's 'identify the symmetry' claim overreaches what the per-texture sensitivity curves show.","tokens_in":6733,"tokens_out":2944,"would_cite":false,"duration_ms":26837,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":false},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"DUNE and T2HK can constrain long-range neutrino-matter interactions to potentials of order 10^-14 to 10^-13 eV, and their combination can identify the underlying U(1)' symmetry in favorable cases.","keywords":["long-range neutrino interactions","DUNE","T2HK","U(1)' symmetries","neutrino oscillations","beyond Standard Model","flavor-dependent matter potential","Z' boson"],"falsifier":"Take early real data from DUNE and T2HK, fit each $V_{\\mathrm{LRI}}$ texture from Fig. 2 to the observed $\\nu_\\mu$ disappearance and $\\nu_e$ appearance rates, and check whether the 2-$\\sigma$ upper limit on $V_{\\mathrm{LRI}}$ falls at or below $10^{-13}$ eV; if the real-data limits are weaker by more than the quoted systematic uncertainties, the forecast is falsified.","tokens_in":5687,"feed_emoji":"⚛️","tokens_out":18114,"duration_ms":138149,"temperature":0.7,"pith_summary":"This paper forecasts how well the next-generation long-baseline neutrino oscillation experiments DUNE and T2HK could detect or rule out new long-range neutrino-matter interactions. It considers fourteen anomaly-free $U(1)^\\prime$ gauge symmetries built from lepton and baryon numbers, each of which would give a distinct flavor-dependent neutrino potential in matter. The central claim is that, regardless of which symmetry is realized, ten years of data from these experiments could constrain the long-range potential to roughly $10^{-14}$ to $10^{-13}$ eV, provided that potential is comparable to the standard oscillation scale. In favorable cases, the pattern of appearance and disappearance signals could single out the $U(1)^\\prime$ symmetry responsible. The tightest projected limits come from muon-neutrino disappearance, while electron-neutrino appearance gives the weakest ones, and this short report defers the full statistical treatment to a companion paper.","feed_headline":"DUNE and T2HK can corner new long-range neutrino forces","feed_subtitle":"Projected limits reach 10^-14 to 10^-13 eV for all 14 candidate U(1)' symmetries.","key_machinery":"The load-bearing object is the long-range matter potential $V_{\\mathrm{LRI}} = \\mathrm{diag}(V_{\\mathrm{LRI},e}, V_{\\mathrm{LRI},\\mu}, V_{\\mathrm{LRI},\\tau})$, added to the standard vacuum and matter terms in the neutrino propagation Hamiltonian $H = H_{\\mathrm{vac}} + V_{\\mathrm{mat}} + V_{\\mathrm{LRI}}$. A new neutral gauge boson $Z^\\prime$ with mass between $10^{-35}$ and $10^{-10}$ eV mediates the interaction, and because its range is so long, neutrinos feel coherent contributions from matter in the Earth, Moon, Sun, Milky Way, and local Universe. The charges of the $U(1)^\\prime$ symmetry fix the texture of $V_{\\mathrm{LRI}}$; that texture determines which oscillation channel carries the signal and therefore how tight the resulting bound is.","core_discovery":"The paper establishes that next-generation long-baseline oscillation experiments can act as a generic probe of long-range neutrino interactions. For each of fourteen $U(1)^\\prime$ symmetries, the new matter potential $V_{\\mathrm{LRI}}$ enters the neutrino propagation Hamiltonian as a diagonal matrix, and the projected $2\\sigma$ sensitivity of DUNE and T2HK, especially in combination, reaches $V_{\\mathrm{LRI}} \\sim 10^{-14}$--$10^{-13}$ eV, comparable to the standard oscillation terms. The texture of $V_{\\mathrm{LRI}}$ determines whether the $\\nu_\\mu \\to \\nu_\\mu$ disappearance channel or the $\\nu_\\mu \\to \\nu_e$ appearance channel is affected, so the pattern of deviations can, in favorable cases, identify the underlying $U(1)^\\prime$ symmetry. The projected limits convert into constraints on the effective coupling $G^\\prime$ of the new mediator versus its mass, and for mediators lighter than roughly $10^{-18}$ eV the projected constraints improve on existing limits.","pith_inferences":["Beyond this paper's explicit forecasts, the same Hamiltonian treatment could be applied to atmospheric neutrinos or neutrino telescopes, whose much longer baselines through the Earth would sample different matter densities and might extend sensitivity to mediator masses outside the range considered here.","The paper's caveat that the new potential must be comparable to the standard oscillation scale implies that optimizing the analysis to the highest-energy bins, where the relevant vacuum Hamiltonian entry scales as $1/E$, could sharpen the projected limits further than the quoted energy-integrated numbers.","A testable extension is to remove individual celestial sources, such as the Earth, Moon, Sun, Milky Way, and local Universe, one at a time from $V_{\\mathrm{LRI}}$ and check which object contributes most of the projected sensitivity; this would tell future analyses where uncertainty in the matter distribution matters most."],"forward_implications":["A combined DUNE+T2HK analysis removes degeneracies between $V_{\\mathrm{LRI}}$, $\\theta_{23}$, $\\delta_{\\mathrm{CP}}$, and the neutrino mass ordering that weaken each experiment's standalone limits.","For all fourteen candidate symmetries, a null result would place upper limits on $V_{\\mathrm{LRI}}$ in the $10^{-14}$--$10^{-13}$ eV range, ruling out long-range interactions with potentials above that scale.","Symmetries whose texture has nonzero entries in the $\\mu$--$\\tau$ sector are constrained most strongly, through $\\nu_\\mu \\to \\nu_\\mu$ disappearance, while textures with a nonzero first diagonal entry are constrained least, through $\\nu_\\mu \\to \\nu_e$ appearance.","If a signal appears, the channel pattern, including which flavors are involved, can distinguish among the candidate $U(1)^\\prime$ symmetries in favorable cases."],"supporting_citations":[{"why":"The companion analysis that defines the Poissonian test statistic, the detector simulations, systematic uncertainties, and the conversion from potential limits to coupling limits.","marker":"[1]"},{"why":"The DUNE design reference that fixes the beam, detector, and exposure used in the forecast.","marker":"[2]"},{"why":"The T2HK (Hyper-Kamiokande) design and technical references that fix the beam, detector, and exposure used in the forecast.","marker":"[3, 4]"},{"why":"Anomaly-free conditions for gauging combinations of lepton and baryon numbers, which justify the fourteen candidate symmetries.","marker":"[5–8]"},{"why":"The global-fit values and 3-sigma ranges of oscillation parameters that the analysis minimizes over.","marker":"[10, 11]"},{"why":"Existing limits from astrophysical flavor measurements that the projected coupling constraints are compared against.","marker":"[12]"}],"fun_headline_variants":["DUNE and T2HK to corner long-range neutrino forces","DUNE and T2HK to probe exotic long-range neutrino forces","DUNE and T2HK could identify new U(1)' symmetries","Long-range neutrino forces face sharp tests from DUNE and T2HK","DUNE and T2HK to constrain ultra-light neutrino mediators"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The projections assume that the way DUNE and T2HK data would be analyzed, including background rates and systematic uncertainties, is realistic; if those systematic errors are underestimated, the quoted limits would be stronger than the experiments can actually achieve.","fun_headline_variants_meta":{"raw":{"variants":["DUNE and T2HK to corner long-range neutrino forces","DUNE and T2HK to probe exotic long-range neutrino forces","DUNE and T2HK could identify new U(1)' symmetries","Long-range neutrino forces face sharp tests from DUNE and T2HK","DUNE and T2HK to constrain ultra-light neutrino mediators"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000683,"raw_usage":{"total_tokens":3130,"prompt_tokens":1004,"completion_tokens":2126,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":620,"completion_tokens_details":{"reasoning_tokens":2034}},"tokens_in":620,"tokens_out":2126,"duration_ms":14429,"temperature":1.0,"reasoning_tokens":2034,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-10T15:32:10.241507+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Take early real data from DUNE and T2HK, fit each $V_{\\mathrm{LRI}}$ texture from Fig. 2 to the observed $\\nu_\\mu$ disappearance and $\\nu_e$ appearance rates, and check whether the 2-$\\sigma$ upper limit on $V_{\\mathrm{LRI}}$ falls at or below $10^{-13}$ eV; if the real-data limits are weaker by more than the quoted systematic uncertainties, the forecast is falsified.","supporting_citations":[],"review_version":1}