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Prospective Sensitivity to Solar Dark Matter using the IceCube Upgrade

T0 review · 2 major / 6 minor · reviewed 2026-08-06 · deepseek-v4-flash

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Pith's one-line read With three years of solar-neutrino data, the IceCube Upgrade is projected to set the best indirect limits on spin-dependent dark matter–proton scattering for masses up to about 210 GeV.

desk verdict A workmanlike, first-of-its-kind sensitivity projection for the IceCube Upgrade's solar dark matter search, but the abstract oversells the reach beyond the computed range and the systematics-free low-energy template deserves caveats. read the letter →

arxiv 2507.14943 v1 pith:QE3X7D7U submitted 2025-07-20 astro-ph.HE

Eliot Genton , Jeffrey Lazar , Carlos Argüelles , Gwenhaël de Wasseige (for the IceCube Collaboration) This is my paper · ORCID
classification astro-ph.HE PACS 95.35.+d95.55.Vj
keywords darkmatterWIMPsolarneutrinosIceCubeUpgradespin-dependentscatteringindirectdetectionneutrinotelescopebinnedPoissonlikelihood
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

Dark matter particles in the weakly interacting massive particle (WIMP) class can be gravitationally captured by the Sun after scattering with solar nuclei, accumulate over the age of the solar system, and annihilate into standard-model particles; the only annihilation products that escape the Sun are neutrinos, producing a faint neutrino flux from the solar direction. This paper projects how well the IceCube Upgrade, a dense new infill of the IceCube neutrino telescope at the South Pole, could detect that flux over three years starting in January 2026. The projected sensitivities would make the Upgrade the most sensitive indirect dark matter search for low masses: best limits on spin-dependent dark matter–proton scattering up to about 210 GeV for the $b\bar{b}$ and $\tau^+\tau^-$ channels, and up to about 20 GeV for neutrino final states, with the reach extending down to $m_\chi \approx 3.7$ GeV. This matters because the GeV-scale mass region is hard for direct-detection experiments, so a solar-neutrino search offers a complementary and potentially superior probe of light dark matter.

What carries the argument

The load-bearing relation is the capture–annihilation equilibrium: for WIMP masses above the ~3.7 GeV evaporation threshold, the annihilation rate approaches half the capture rate, so the solar neutrino flux at Earth is directly proportional to the spin-dependent DM–proton scattering cross section $\sigma^{SD}_{\chi p}$. On top of this, the analysis machinery is a three-dimensional template search: simulated signal and background events are binned in reconstructed energy, angular separation from the Sun, and track score, where track score is a classifier that separates muon-neutrino charged-current events (tracks) from other topologies (cascades). A binned Poisson likelihood with a test-statistic threshold at the 90th percentile of the background-only distribution converts the templates into projected limits, with backgrounds from atmospheric muons, conventional atmospheric neutrinos, and solar atmospheric neutrinos generated from the IC93 simulation.

What would settle it

Compare the projected 90% confidence-level sensitivity curves in Fig. 6 with the actual upper limits on $\sigma^{SD}_{\chi p}$ that IceCube reports from the first three years of IC93 data; if the observed limits lie significantly above the projected band, the detector simulation or background model is wrong. A faster check is to measure the IC93 effective area and angular resolution with well-known atmospheric neutrino fluxes in the first year of data and compare them with the simulation curves in Fig. 2.

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Extended reading notes

Core claim

The central claim is that the IceCube Upgrade, using a template-based search for a neutrino excess from the Sun, will achieve the best sensitivity to low-mass dark matter annihilation from the Sun: world-leading projected limits on the spin-dependent DM–proton scattering cross section $\sigma^{SD}_{\chi p}$ for masses below about 100 GeV, and the best overall sensitivity up to about 210 GeV for the $b\bar{b}$ and $\tau^+\tau^-$ channels and up to about 20 GeV for neutrino final states, after three years of data. The analysis uses Monte Carlo templates binned in reconstructed energy, angular separation from the Sun, and track score, and translates an annihilation neutrino flux into a scattering cross section through the capture–annihilation equilibrium relation, assuming no evaporation for $m_\chi \gtrsim 3.7$ GeV. The $b\bar{b}$ channel's low-mass reach is limited to about 10 GeV by the hadronization modeling, while the sensitivity is evaluated with a binned Poisson likelihood and a background consisting of atmospheric muons, conventional atmospheric neutrinos, and solar atmospheric neutrinos.

Load-bearing premise

The projected limits rest on the assumption that the simulated IceCube Upgrade detector response (effective area and angular resolution) and the modeled background rates (atmospheric muons, atmospheric neutrinos, and solar atmospheric neutrinos) are accurate, with no systematic uncertainties folded in; if the simulation is optimistic or the backgrounds are mis-normalized, the quoted cross-section limits would shift.

Editorial extensions

If this is right

  • A null result with three years of IC93 data would place the strongest indirect constraints on spin-dependent WIMP–proton scattering for masses below about 100 GeV.
  • The search extends IceCube's solar dark matter sensitivity down from roughly 100 GeV to about 3.7 GeV, opening the GeV-mass window to neutrino telescopes.
  • The track-score separation between cascade-like and track-like events is what makes the $\tau^+\tau^-$ and $\nu\bar{\nu}$ channels competitive at low mass, since those channels produce more cascades than muon tracks.
  • If a dark matter signal is present, the reconstructed energy spectrum of the solar neutrino excess would discriminate between annihilation channels, from the soft $b\bar{b}$ spectrum to the monochromatic $\nu\bar{\nu}$ line.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • An implicit corollary is that solar-neutrino searches may become the strongest probe of low-mass spin-dependent WIMP scattering in the coming decade, a role usually associated with direct-detection experiments.
  • The same template, track-score, and likelihood machinery could be aimed at WIMP annihilation in the Earth's core, where capture is dominated by spin-independent scattering, giving the Upgrade access to a complementary interaction type; this extension is not discussed in the paper.
  • Because the projection includes no systematic uncertainties, the real limits could be worse if the solar atmospheric neutrino flux is higher than modeled, and a first-year measurement of that flux would sharpen the projection.
  • If a future direct-detection experiment also sees a signal in the 4–210 GeV range, combining it with the solar-capture measurement would test whether the captured particle matches the local dark matter density and cross-section expectations.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

2 major / 6 minor

Summary. This proceedings paper projects the sensitivity of the IceCube Upgrade (IC93) to spin-dependent dark matter-proton scattering, using neutrinos from WIMP annihilation in the Sun. The analysis constructs signal and background templates from Monte Carlo simulations, bins events in reconstructed energy, angular separation from the Sun, and track score, and derives 90% sensitivity limits from binned Poisson likelihood pseudo-experiments. Results are presented for DM masses between roughly 3 GeV and 500 GeV for the b-bbar, tau+tau-, and neutrino annihilation channels, with the claim that the Upgrade would be the most sensitive indirect detection experiment below O(100) GeV and, in the abstract, over the range 3 GeV to 10 TeV.

Significance. If the projections are correct, the IceCube Upgrade would provide the strongest indirect limits on spin-dependent DM-proton scattering at low masses, complementing and potentially exceeding existing limits from PICO, Super-K, ANTARES, and IceCube. The analysis is a transparent sensitivity study: it uses a standard capture-rate formalism, full detector simulation, three annihilation channels, and pseudo-experiments to define the sensitivity, and it makes no fitted-to-data claims. The main value is in quantifying the Upgrade's low-energy reach, which is a timely input for the community. However, the strength of the conclusions is tempered by the absence of systematic uncertainties and by an abstract claim that extends beyond the computed range.

major comments (2)
  1. [Abstract and Sec. 4 / Fig. 6] The abstract states that these sensitivities make IceCube the most sensitive indirect detection experiment for DM in the range from 3 GeV to 10 TeV, but the analysis is restricted to DM masses between 3 GeV and 500 GeV and Fig. 6 displays only 10-500 GeV. No sensitivity calculation or comparison is shown above 500 GeV, so the 10 TeV claim is unsupported by the presented work. Please either remove the 10 TeV claim, limit it to the computed range, or extend the calculation and comparison to higher masses.
  2. [Sec. 3, Eq. (2) and Fig. 6] The likelihood uses a single background normalization parameter alpha_bg with no systematic uncertainties, while the projected world-leading sensitivity below ~100 GeV is driven by low-energy, cascade-dominated events whose simulated angular resolution and effective area (Fig. 2) are not yet validated against data because the Upgrade is not built. A modest degradation in the simulated angular resolution at 3-30 GeV, or a shift in the atmospheric background normalization, could move the projected curves above the existing limits in Fig. 6 and remove the claimed advantage. The authors should quantify this robustness, for example by rescaling the angular smearing and background normalization in the pseudo-experiments, or explicitly state the absence of such systematics as a limitation.
minor comments (6)
  1. [Sec. 2, Fig. 2] The text and Fig. 2 refer to the upgraded configuration as IC94 in one place while the title, abstract, and rest of the paper use IC93; please harmonize the detector configuration naming.
  2. [Sec. 3, Eq. (3)] The notation 'check alpha_x' in Eq. (3) is not defined clearly; please specify that these are the best-fit parameters under the background-only hypothesis and define them consistently with Eq. (4).
  3. [References [13] and [15]] References [13] and [15] use incomplete author labels ('A.-M. et al.' and 'C. A. et al.'); please provide full author lists or collaboration names.
  4. [Sec. 3, capture rate formula] The projected limits scale linearly with the assumed local dark matter density and velocity dispersion in the capture-rate formula, but the paper does not discuss this dependence; a sentence noting the scaling and the benchmark choices would help readers assess the halo-parameter uncertainty.
  5. [Sec. 4, Fig. 6] The text says the minimum DM mass tested is 3.7 GeV, but the horizontal axis of Fig. 6 starts at 10 GeV; please extend the figure to show the low-mass region or explain the chosen axis range.
  6. [Fig. 3] In Fig. 3, the label 'm_chi = 13 GeV' appears twice and only one 'm_chi = 63 GeV' label is present; please make the channel-to-curve correspondence unambiguous.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the projected sensitivity is obtained from Monte Carlo templates and a binned Poisson likelihood, with no parameter fitted to data, and the self-cited flux tool is not used as an unverified load-bearing premise.

full rationale

The derivation chain is self-contained as a sensitivity projection. The capture-rate expression is taken from standard literature [5] with fixed benchmark halo inputs (0.3 GeV/cm^3, 270 km/s), and the evaporation threshold from Gould [6]. Neutrino fluxes are computed with the χaroν tool [8,9]; although this is a self-citation by overlapping authors, it is a computational tool rather than a fitted parameter or a uniqueness theorem, and the paper does not define the predicted cross-section in terms of the tool's output by construction. Signal and background templates are generated from IC93 Monte Carlo simulations and flux models (Gaisser H4a + SIBYLL, Honda2014), and the sensitivity is obtained from pseudo-experiments using a binned Poisson likelihood with TS threshold 1.64. No quantity labeled a 'prediction' is a fitted input: the signal normalization is a free parameter scanned in trials, and the projected cross-section limit scales linearly from a fixed reference cross-section. The comparison limits in Fig. 6 are external experimental results, not inputs to the generation of the projected curves. The abstract's statement '3 GeV to 10 TeV' exceeds the computed mass range (up to 500 GeV in the text and 10-500 GeV in Fig. 6), but this is an internal overstatement or correctness risk, not circularity, because no reduction of the claimed sensitivity to its own inputs is exhibited. Overall, no circular step is present, so the circularity score is 0.

Assumptions & free parameters 0 free parameters · 5 assumptions · 0 invented entities

The paper introduces no new particles, forces, or free parameters. It inherits the standard WIMP capture-annihilation formalism (Jungman et al., Gould), a standard halo model with local density 0.3 GeV/cm^3 and velocity dispersion 270 km/s, and assumes annihilation equilibrium, negligible evaporation above 3.7 GeV, and that neutrinos are the only observable escaping the Sun. These are domain assumptions taken from prior literature, stated in Section 3.

assumptions (5)
  • domain assumption Annihilation equilibrium is reached for the Sun, so the annihilation rate equals half the capture rate.
    Section 3 uses Gamma_A ~ 1/2 C, assuming the solar system age exceeds the equilibration time tau, which requires C and C_A to be large enough.
  • domain assumption DM evaporation is negligible for masses above 3.7 GeV.
    Section 3 and Section 4 cite Gould (1987) for the evaporation threshold; the analysis is restricted to masses above this limit.
  • domain assumption Standard halo model with local density 0.3 GeV/cm^3 and velocity dispersion 270 km/s.
    The capture rate formula in Section 3 uses these benchmark values, which are inputs from the literature rather than fitted parameters.
  • domain assumption Neutrinos are the only Standard Model particles that escape the Sun after DM annihilation.
    Section 1 states this premise, which justifies the search for a neutrino excess from the solar direction.
  • domain assumption The 'χaroν' tool and PYTHIA produce reliable neutrino fluxes and hadronic decays in the mass range considered.
    Section 4 notes that PYTHIA is not reliable below about 10 GeV for hadronic channels, setting the lower mass limit for the b bbar channel.

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Cite this review

Pith. "Pith review of Prospective Sensitivity to Solar Dark Matter using the IceCube Upgrade." pith.science (2026). https://pith.science/paper/QE3X7D7U

@misc{pith2026250714943,
  author       = {Pith},
  title        = {Pith review of: Prospective Sensitivity to Solar Dark Matter using the IceCube Upgrade},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/QE3X7D7U}},
  note         = {Machine review of arXiv:2507.14943}
}
read the original abstract

While astrophysical observations imply that 85% of the matter content is unaccounted for, the nature of this dark matter (DM) component remains unknown. Weakly Interacting Massive Particles (WIMPs) - DM particles that interact at or below the weak interaction scale - could naturally explain this missing matter. These interactions with the Standard Model (SM) allow them to be gravitationally captured in celestial bodies like the Sun. Trapped DM in the solar core could subsequently annihilate, producing stable SM particles, of which only neutrinos can escape the Sun's dense interior. Therefore, an excess of neutrinos originating from the direction of the Sun would serve as evidence of DM. The IceCube Upgrade, a dense infill of the IceCube Neutrino Observatory, will lower the energy threshold and improve sensitivity in the range from 1 to 500 GeV, thereby enhancing IceCube's ability to detect GeV-scale DM. In this contribution, I present projections of the IceCube Upgrade's sensitivity to the DM-proton scattering cross section for DM masses between 3 GeV and 500 GeV. These sensitivities position IceCube as the most sensitive indirect detection experiment for DM in the mass range from 3 GeV to 10 TeV.

Figures

Figures reproduced from arXiv: 2507.14943 by the authors.

Figure 1
Figure 1. Top-down View of IceCube Detector. Each point marks a string of optical modules, with symbols indicating sub-detectors. The enlarged view highlights the denser DeepCore and Upgrade regions. 101 102 Eν [GeV] 10−8 10−6 10−4 10−2 A ν+¯ν eff [m 2 ] IC86 IC93 (a) Effective area 101 102 Eν [GeV] 0 20 40 60 80 100 ∆Ψ ν+¯ν [°] IC86 IC93 θνl (b) Angular Resolution [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. Detector response comparison between Upgrade and DeepCore. Left: effective area as a function of neutrino energy. Right: angular resolution (median angle between true and reconstructed direction) as a function of energy; the band shows the 1𝜎 containment region. The black line indicates median angular separation between the neutrino and lepton in charged-current interactions from the simulation dataset processed wit… view at source ↗
Figure 3
Figure 3. Neutrino flux for different annihilation channels The line indicates the neutrino flux at the detector for different initial DM mass and for a nominal 𝜎𝜒 𝑝 = 1 × 10−40 cm2 weighted by the product of their MC weight and neutrinos from DM anhilation flux from the 𝜒aro𝜈 tool [8, 9]. Three representative WIMP annihilation channels are considered: 𝑏𝑏¯, which produces hadronic final states and results in a soft neutrino e… view at source ↗
Figures from the paper (3 more)
Figure 4
Figure 4. Figure 4: Example signal distribution for solar DM. Simulated for DM with mass 𝑚𝜒 = 63 GeV and scattering cross-section 𝜎𝜒 𝑝 = 1 × 10−40 cm2 , annihilating to 𝑏𝑏¯ from the solar core. The distribution is binned in reconstructed energy, angular separation from the Sun, and track …
Figure 5
Figure 5. Figure 5: Background distribution for solar analysis. Contributions include solar and conventional atmospheric neutrinos and atmospheric muons. Noise events are excluded at final selection level. the normalization parameters for the potential signal, 𝛼𝜒 (DM-induced solar neutrin…
Figure 6
Figure 6. Figure 6: Sensitivity to DM-proton scattering 𝜎𝜒 𝑝 with three years of data. These projected limits from the IceCube Upgrade would extend IceCube’s reach down to 3 GeV, offering complementarity to the lowest masses probed by direct detection experiments. Furthermore, the IceCube…

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Works this paper leans on

16 extracted references · 14 canonical work pages

  1. [1]

    SNO Collaboration Collaboration, Q. R. Ahmadet al., Phys. Rev. Lett. 87 (2001) 071301

    work page 2001

  2. [2]

    Schumann,J

    M. Schumann,J. Phys. G 46 no. 10, (2019) 103003

    work page 2019

  3. [3]

    IceCubeCollaboration, M. G. Aartsenet al., JINST 12 no. 03, (2017) P03012. [Erratum: JINST 19, E05001 (2024)]

    work page 2017

  4. [4]

    Ishihara,PoS ICRC2019(2021) 1031

    IceCubeCollaboration, A. Ishihara,PoS ICRC2019(2021) 1031

    2021

  5. [5]

    Jungman, M

    G. Jungman, M. Kamionkowski, and K. Griest,Physics Reports 267 no. 5, (1996) 195–373

    work page 1996

  6. [6]

    Gould,Astrophys

    A. Gould,Astrophys. J. 321 (1987) 560

    work page 1987

  7. [7]

    PAL: A Positional Astronomy Library,

    T. Jenness and D. S. Berry, “PAL: A Positional Astronomy Library,” inAstronomical Data Analysis, D. N. Friedel, ed., vol. 475, pp. 307–310. San Francisco, CA, USA, 2013. Available athttps://aspbooks.org/publications/475/307.pdf

    work page 2013

  8. [8]

    Meftah, M., Corbard, T., Hauchecorne, A., Morand, F., Ikhlef, R., Chauvineau, B., Renaud, C., Sarkissian, A., and Damé, L.,A&A 616 (2018) A64

    work page 2018

Show all 16 references
  1. [9]

    Q. Liu, J. Lazar, C. A. Argüelles, and A. Kheirandish,Journal of Cosmology and Astroparticle Physics 2020no. 10, (Oct., 2020) 043–043

    2020

  2. [10]

    T. K. Gaisser,Astroparticle Physics 35(2012) 801–806

    2012

  3. [11]

    R. S. Fletcher, T. K. Gaisser, P. Lipari, and T. Stanev,Phys. Rev. D 50(1994) 5710–5731

    1994

  4. [12]

    Wren,Neutrino Mass Ordering Studies with IceCube-DeepCore

    S. Wren,Neutrino Mass Ordering Studies with IceCube-DeepCore. Phd thesis, University of Manchester, 2018

    2018

  5. [13]

    et al.,Physics Letters B 759 (Aug., 2016) 69–74

    A.-M. et al.,Physics Letters B 759 (Aug., 2016) 69–74

    2016

  6. [14]

    Search for neutrinos from annihilation of captured low-mass dark matter particles in the sun by super-kamiokande,

    K. Collaboration, “Search for neutrinos from annihilation of captured low-mass dark matter particles in the sun by super-kamiokande,” 2015.https://arxiv.org/abs/1503.04858

    2015 arXiv

  7. [15]

    C. A. et al.,Physical Review D 100 no. 2, (Jul, 2019) 022001

    2019

  8. [16]

    Sjöstrand, S

    T. Sjöstrand, S. Ask, J. R. Christiansen, R. Corke, N. Desai, P. Ilten, S. Mrenna, S. Prestel, C. O. Rasmussen, and P. Z. Skands,Computer Physics Communications 191 (June, 2015) 159–177. 8 IceCube Upgrade Sensitivity to WIMP annhilation in the core of the Sun Full Author List:...

    2015

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