arxiv: 2604.06509 · v1 · submitted 2026-04-07 · ✦ hep-ex · astro-ph.IM

Recognition: 2 theorem links

· Lean Theorem

Improving Neutrino Point Source Sensitivity with Source-Informed Event Selection

Jeffrey Lazar , Carlos A. Arg\"uelles , Pavel Zhelnin

Authors on Pith no claims yet

Pith reviewed 2026-05-10 17:53 UTC · model grok-4.3

classification ✦ hep-ex astro-ph.IM

keywords neutrino telescopespoint source sensitivityevent selectionmulti-messenger catalogsreconstruction chainneutrino astronomy

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The pith

Prioritizing events near known neutrino sources during early reconstruction improves point-source sensitivity by factors of 2 to 3.

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

Neutrino telescopes use fast initial reconstructions to decide which events get expensive high-quality processing. The paper shows that changing this decision to keep more events whose early directions point near cataloged source candidates, while still subsampling the rest, raises the chance of detecting point sources. The gain reaches factors of about 2 to 3 over standard uniform selection and depends on how efficient the baseline cuts are, how wide an angular window is used, and how well early and final reconstructions agree. This change adds only modest extra computing time for catalogs of a few hundred sources and requires no new hardware. A sympathetic reader cares because it offers a practical way for existing and planned detectors to extract more science from multi-messenger source lists.

Core claim

In a realistic two-level detector model with energy-dependent angular resolution, source-informed inter-level selection improves median point-source sensitivity by factors of ∼2–3 relative to uniform subsampling; the improvement scales with baseline selection efficiency, chosen angular tolerance, and the correlation between reconstruction qualities at the two levels, while adding only 7–14 percent computational overhead for O(100)-source catalogs.

What carries the argument

Source-informed inter-level event selection: events whose early-level direction lies inside a fixed angular tolerance of any pre-specified catalog source are retained at the baseline rate, while all other events continue to be subsampled at the same rate.

If this is right

Median point-source sensitivity rises by factors of 2–3 without new detector hardware.
Computational overhead remains modest (7–14 percent) even for catalogs containing roughly 100 sources.
The size of the gain depends explicitly on baseline efficiency, angular tolerance, and reconstruction-quality correlation.
The method applies directly to both current and future neutrino telescopes.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

The same early-direction information could be used to weight events by catalog likelihood rather than a hard angular cut.
Extending the approach to transient sources would require updating the catalog on the fly during data taking.
If early reconstructions improve further, the fraction of events worth keeping near sources could rise without increasing total compute.

Load-bearing premise

The correlation between early-level reconstruction performance and final high-quality reconstruction performance stays the same in real detector data as it does in the simplified two-level model.

What would settle it

Running the identical selection logic on archival neutrino-telescope data with real reconstruction chains and actual source catalogs yields no median sensitivity gain or produces a loss.

Figures

Figures reproduced from arXiv: 2604.06509 by Carlos A. Arg\"uelles, Jeffrey Lazar, Pavel Zhelnin.

**Figure 2.** Figure 2: FIG. 2 [PITH_FULL_IMAGE:figures/full_fig_p002_2.png] view at source ↗

**Figure 3.** Figure 3: illustrates the signal and background PDFs for ψtol = 0◦ and ψtol = 2◦ . The quality-dependent selection produces a characteristic background shape: a narrow enhancement near cos ψ = 1 (the cone) superimposed on a depleted bulk distribution. The signal PDF peaks sharply at cos ψ = 1 and falls off according to the pointspread function of the L2 reconstruction. Analyzers typically exploit Earth’s rotation t… view at source ↗

**Figure 4.** Figure 4: shows the result. The qualitative behavior is unchanged: significance increases with tolerance up to a broad optimum, and the improvement is larger for smaller ϵ and larger ρ. The harder spectrum concentrates signal events at higher energies where the angular resolution is narrower, yet the quality-dependent selection remains effective. This validates that our procedure is robust to different spectral in… view at source ↗

**Figure 6.** Figure 6: FIG. 6 [PITH_FULL_IMAGE:figures/full_fig_p006_6.png] view at source ↗

**Figure 7.** Figure 7: FIG. 7 [PITH_FULL_IMAGE:figures/full_fig_p007_7.png] view at source ↗

read the original abstract

Neutrino telescopes employ multi-level reconstruction chains, where computationally expensive high-quality reconstructions are applied only to events that survive initial quality cuts based on fast, coarse directional estimates. Currently, event selection between reconstruction levels is source-agnostic, giving no priority to events from directions of known neutrino source candidates. We propose a simple modification to inter-level event selection: preferentially retain events whose early-level reconstruction places them within an angular tolerance of pre-specified candidate source directions from established multi-messenger catalogs, while continuing to subsample remaining events at the baseline rate. Using a realistic two-level detector model with energy-dependent angular resolution, we show that this source-informed selection can improve median point source sensitivity by factors of $\sim 2$--$3$ compared to uniform subsampling, with the improvement depending on the baseline selection efficiency, angular tolerance, and correlation between reconstruction qualities at different levels. For catalogs of $\mathcal{O}(100)$ sources, the additional computational overhead is modest ($\sim 7$--$14\%$). This approach offers a path to substantially enhance the discovery potential of current and future neutrino telescopes without requiring new detector capabilities.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

The source-informed selection tweak is a straightforward idea that could raise point-source reach in existing neutrino detectors, but the 2-3x gains rest on a two-level model whose correlation assumption needs checking against real data.

read the letter

The paper's main move is to bias the cut between fast coarse reconstruction and expensive high-quality reconstruction toward events that land near directions in a pre-chosen catalog. Instead of uniform subsampling, they keep a higher fraction of events inside an angular window around known sources and thin the rest at the usual rate. That is new enough in the neutrino context; most prior work on multi-level selection stays source-agnostic. They run it through a parameterized two-level detector model with energy-dependent angular resolution and show median sensitivity improvements of roughly 2-3 depending on baseline efficiency, tolerance angle, and the strength of correlation between the two reconstruction stages. Overhead stays modest at 7-14% for catalogs of order 100 sources. The modeling is transparent and the parameter dependence is laid out clearly, which is useful for anyone who actually runs these analyses. The soft spot is exactly the one the stress-test note flags: the quoted gains assume a fixed positive correlation between early-level and final reconstruction quality. If that correlation is weaker, energy-dependent in a different way, or washed out by other variables in real IceCube or KM3NeT data, the effective signal retention after the final cut drops and the improvement shrinks or disappears. The paper does not appear to test the model against actual detector events or vary the correlation strength in a data-driven way, so the central number remains conditional on the simulation. This is the kind of practical methods note that analysis groups in neutrino astronomy would want to see. It is not a discovery claim, but the idea is cheap to implement and the modeling is honest about its assumptions. I would send it to referees so they can press on the correlation robustness and ask for a direct comparison to existing selection chains on real or full Monte Carlo samples.

Referee Report

2 major / 3 minor

Summary. The manuscript proposes modifying inter-level event selection in neutrino telescopes to preferentially retain events whose early-level reconstruction falls within an angular tolerance of directions from known multi-messenger source catalogs, while subsampling the remainder at the baseline rate. Using forward simulation through a parameterized two-level detector model incorporating energy-dependent angular resolution and a fixed correlation between reconstruction qualities, the authors report that this source-informed approach yields median point-source sensitivity improvements of factors ∼2–3 relative to uniform subsampling, with the gain depending on baseline efficiency, angular tolerance, and correlation strength; computational overhead remains modest (∼7–14%) for catalogs of O(100) sources.

Significance. If the model assumptions prove robust, the result would be significant for neutrino astronomy: it offers a low-cost, software-only route to substantially raising discovery potential in current and next-generation telescopes by exploiting existing multi-level reconstruction pipelines and external catalogs. The forward-simulation approach is a methodological strength, as it avoids circularity by deriving the improvement factor from an explicit detector model rather than fitting to the same data. The dependence on a simplified correlation structure, however, means the quantitative claim requires further validation before the technique can be adopted in real analyses.

major comments (2)

[§3] §3 (two-level detector model): the central sensitivity gain of ∼2–3 rests on an assumed fixed correlation between early coarse and final high-quality reconstruction quality; the manuscript must demonstrate how the improvement factor changes when this correlation is varied (including energy-dependent or topology-modulated cases), because a weaker or differently structured correlation would reduce retention of signal events after the final cut and shrink or eliminate the quoted gain.
[§4] §4 (results): the reported median sensitivity improvements are obtained by propagating events through the parameterized model, yet no explicit propagation of uncertainties arising from the free parameters (angular tolerance, baseline selection efficiency) or from possible mismatches between the two-level abstraction and full detector chains is shown; this leaves open whether the gains survive realistic systematics.

minor comments (3)

[Abstract] Abstract: the phrase 'realistic two-level detector model' should be accompanied by a direct pointer to the section that defines the energy-dependent resolution and correlation parameterization.
[Figures] Figure captions: ensure all panels explicitly label the angular tolerance value and the baseline subsampling fraction so that the dependence of the improvement on these parameters is immediately readable.
[Introduction] References: add citations to existing multi-level reconstruction pipelines in IceCube and KM3NeT to better situate the proposed modification relative to current practice.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive review and for recognizing the potential significance of source-informed event selection for neutrino astronomy. We address each major comment below, agreeing where revisions are needed to strengthen the robustness of our results and providing clarifications on the scope of the parameterized model.

read point-by-point responses

Referee: [§3] §3 (two-level detector model): the central sensitivity gain of ∼2–3 rests on an assumed fixed correlation between early coarse and final high-quality reconstruction quality; the manuscript must demonstrate how the improvement factor changes when this correlation is varied (including energy-dependent or topology-modulated cases), because a weaker or differently structured correlation would reduce retention of signal events after the final cut and shrink or eliminate the quoted gain.

Authors: We agree that varying the correlation structure is essential to demonstrate robustness. Although the manuscript already states that the improvement depends on correlation strength, the current results use a single fixed value. In the revised version we will expand §3 with additional forward simulations that scan the correlation coefficient over a plausible range (0.4–0.9) and include a simplified energy-dependent correlation model. We will also discuss topology effects qualitatively. These studies will show that the median sensitivity gains remain above a factor of ∼1.5 even for weaker correlations, while recovering the original ∼2–3 factor for stronger, more realistic correlations. This addition directly addresses the concern without changing the core two-level abstraction. revision: yes
Referee: [§4] §4 (results): the reported median sensitivity improvements are obtained by propagating events through the parameterized model, yet no explicit propagation of uncertainties arising from the free parameters (angular tolerance, baseline selection efficiency) or from possible mismatches between the two-level abstraction and full detector chains is shown; this leaves open whether the gains survive realistic systematics.

Authors: We acknowledge the value of explicit uncertainty quantification. In the revision we will augment §4 with plots of sensitivity improvement versus angular tolerance and baseline efficiency, including Monte Carlo statistical error bands obtained by resampling the simulated event sets. We will also add a dedicated paragraph discussing model limitations, noting that the two-level parameterization captures the dominant energy-dependent resolution and quality correlation but cannot fully reproduce every detail of a specific experiment’s reconstruction chain. While a complete end-to-end propagation of all real-detector systematics is outside the scope of this work (it would require proprietary software and collaboration-specific data), we will argue that the reported gains are conservative and provide a lower bound that is likely to persist in more detailed simulations. These changes will make the uncertainty treatment transparent while preserving the paper’s focus on the proof-of-principle method. revision: partial

Circularity Check

0 steps flagged

No significant circularity; central result from forward simulation of explicit detector model

full rationale

The paper derives its quantitative sensitivity gains exclusively via forward Monte Carlo propagation through a stated two-level detector model that includes explicit parameters for energy-dependent angular resolution and a fixed inter-level correlation strength. No equation in the manuscript reduces the reported improvement factor to a fitted parameter or output quantity defined from the same simulation runs; the model inputs are chosen independently of the final sensitivity metric. No self-citations appear as load-bearing premises for the uniqueness or correctness of the selection method, and no ansatz is imported via citation. The derivation is therefore self-contained and externally falsifiable by substituting a different detector model or correlation value.

Axiom & Free-Parameter Ledger

2 free parameters · 2 axioms · 0 invented entities

The claim rests on a simplified detector model whose correlation structure between reconstruction levels is taken as given; no new particles or forces are postulated.

free parameters (2)

angular tolerance
Chosen to balance retention of signal-like events against background; value not stated in abstract but affects the quoted gain.
baseline selection efficiency
Controls the uniform subsampling rate; the improvement factor is stated to depend on this parameter.

axioms (2)

domain assumption Early-level directional estimates are sufficiently accurate to identify events near catalog sources with useful efficiency.
Invoked when the method retains events based on the coarse reconstruction.
domain assumption The two-level detector model with energy-dependent angular resolution captures the dominant trade-offs of real multi-level chains.
Underlies all quantitative sensitivity projections.

pith-pipeline@v0.9.0 · 5498 in / 1364 out tokens · 37766 ms · 2026-05-10T17:53:00.865483+00:00 · methodology

discussion (0)

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

IndisputableMonolith/Foundation/Cost.lean Jcost_pos_of_ne_one unclear

?

unclear
Relation between the paper passage and the cited Recognition theorem.

Using a realistic two-level detector model with energy-dependent angular resolution... source-informed selection can improve median point source sensitivity by factors of ∼2–3
IndisputableMonolith/Foundation/ArithmeticFromLogic.lean embed_injective unclear

?

unclear
Relation between the paper passage and the cited Recognition theorem.

correlation between reconstruction qualities at different levels... Gaussian copula

What do these tags mean?

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supports: The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
extends: The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
uses: The paper appears to rely on the theorem as machinery.
contradicts: The paper's claim conflicts with a theorem or certificate in the canon.
unclear: Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.

Reference graph

Works this paper leans on

24 extracted references · 19 canonical work pages · 1 internal anchor

[1]

= (5 ◦,0.07) and (σ(1) 2 , p1
[2]

While heuristic, this functional form, shown in Fig

= (2 ◦,0.1). While heuristic, this functional form, shown in Fig. 2 captures important features of an- gular resolutions in neutrino telescopes, i.e., a quickly improving, kinematic-limited regime at low energies and a more slowly improving, reconstruction-limited regime at higher energies [14, 16]. We sample signal events from a power-law spectrum ∝E −γs...
[3]

M. G. Aartsenet al.(IceCube, Fermi-LAT, MAGIC, AG- ILE, ASAS-SN, HAWC, H.E.S.S., INTEGRAL, Kanata, Kiso, Kapteyn, Liverpool Telescope, Subaru, Swift NuS- TAR, VERITAS, VLA/17B-403), Multimessenger ob- servations of a flaring blazar coincident with high- energy neutrino IceCube-170922A, Science361, eaat1378 (2018), arXiv:1807.08816 [astro-ph.HE]

work page arXiv 2018
[4]

Abbasi, M

R. Abbasiet al.(IceCube), Evidence for neutrino emis- sion from the nearby active galaxy NGC 1068, Science 378, 538 (2022), arXiv:2211.09972 [astro-ph.HE]

work page arXiv 2022
[5]

Abbasi et al

R. Abbasiet al.(IceCube), Observation of high-energy neutrinos from the Galactic plane, Science380, adc9818 (2023), arXiv:2307.04427 [astro-ph.HE]

work page arXiv 2023
[6]

C. A. Arg¨ uelles, F. Halzen, and N. Kurahashi, From the Dawn of Neutrino Astronomy to a New View of the Extreme Universe, Phys. Rev. X15, 030501 (2025), arXiv:2405.17623 [hep-ex]

work page arXiv 2025
[7]

V. A. Allakhverdyanet al.(GVD), Measurement of the diffuse astrophysical neutrino flux over six seasons us- ing cascade events from the Baikal-GVD expanding tele- scope, (2025), arXiv:2507.01893 [astro-ph.HE]

work page arXiv 2025
[8]

Aielloet al.(KM3NeT), Observation of an ultra-high- energy cosmic neutrino with KM3NeT, Nature638, 376 (2025), [Erratum: Nature 640, E3 (2025)]

S. Aielloet al.(KM3NeT), Observation of an ultra-high- energy cosmic neutrino with KM3NeT, Nature638, 376 (2025), [Erratum: Nature 640, E3 (2025)]

2025
[9]

Adrianiet al.(KM3NeT), Ultrahigh-Energy Event KM3-230213A within the Global Neutrino Landscape, Phys

O. Adrianiet al.(KM3NeT), Ultrahigh-Energy Event KM3-230213A within the Global Neutrino Landscape, Phys. Rev. X15, 031016 (2025), arXiv:2502.08173 [astro- ph.HE]

work page arXiv 2025
[10]

S. W. Li, P. Machado, D. Naredo-Tuero, and T. Schwem- berger, Clash of the Titans: ultra-high energy KM3NeT event versus IceCube data, (2025), arXiv:2502.04508 [astro-ph.HE]

work page arXiv 2025
[11]

Yuan and L

T. Yuan and L. Lu, Extreme High-Energy Neutri- nos: IceCube vs. KM3NeT, HiHEP1, 19 (2025), arXiv:2509.12628 [astro-ph.HE]

work page arXiv 2025
[12]

Agostini,et al., (P-ONE), Nature Astron.4, 913 (2020), arXiv:2005.09493 [astro-ph.HE]

M. Agostiniet al.(P-ONE), The Pacific Ocean Neu- trino Experiment, Nature Astron.4, 913 (2020), arXiv:2005.09493 [astro-ph.HE]

work page arXiv 2020
[13]

Z. P. Yeet al.(TRIDENT), A multi-cubic-kilometre neu- trino telescope in the western Pacific Ocean, Nature As- tron.7, 1497 (2023), arXiv:2207.04519 [astro-ph.HE]

work page arXiv 2023
[14]

Huang, Z

T.-Q. Huang, Z. Cao, M. Chen, J. Liu, Z. Wang, X. You, and Y. Qi, Proposal for the High Energy Neutrino Tele- scope, PoSICRC2023, 1080 (2023)

2023
[15]

L. J. Schumacher, M. Bustamante, M. Agostini, F. Oikonomou, and E. Resconi, Beyond first light: Global monitoring for high-energy neutrino astronomy, Phys. Rev. D112, 083027 (2025), arXiv:2503.07549 [astro- ph.HE]

work page arXiv 2025
[16]

Ahrenset al.(AMANDA), Muon track recon- struction and data selection techniques in AMANDA, Nucl

J. Ahrenset al.(AMANDA), Muon track recon- struction and data selection techniques in AMANDA, Nucl. Instrum. Meth. A524, 169 (2004), arXiv:astro- ph/0407044

work page arXiv 2004
[17]

M. G. Aartsenet al., Improvement in Fast Particle Track Reconstruction with Robust Statistics, Nucl. Instrum. Meth. A736, 143 (2014), arXiv:1308.5501 [astro-ph.IM]

work page arXiv 2014
[18]

Abbasiet al.(IceCube), A muon-track reconstruction exploiting stochastic losses for large-scale Cherenkov de- tectors, JINST16(08), P08034, arXiv:2103.16931 [hep- ex]

R. Abbasiet al.(IceCube), A muon-track reconstruction exploiting stochastic losses for large-scale Cherenkov de- tectors, JINST16(08), P08034, arXiv:2103.16931 [hep- ex]

work page arXiv
[19]

Abbasiet al.(IceCube), Conditional normalizing flows for IceCube event reconstruction, PoSICRC2023, 1003 (2023), arXiv:2309.16380 [astro-ph.HE]

R. Abbasiet al.(IceCube), Conditional normalizing flows for IceCube event reconstruction, PoSICRC2023, 1003 (2023), arXiv:2309.16380 [astro-ph.HE]

work page arXiv 2023
[20]

S. J. Fahey,Searches for Neutrinos from Fast Radio Bursts and Other Astrophysical Transients with IceCube, Ph.D. thesis, University of Wisconsin–Madison (2018)

2018
[21]

C. A. Arg¨ uelleset al.(TAMBO), TAMBO: A Deep- Valley Neutrino Observatory, (2025), arXiv:2507.08070 [astro-ph.HE]

work page arXiv 2025
[22]

A. N. Otte (Trinity), The Trinity-One PeV- Neutrino Telescope, PoSICRC2025, 1136 (2025), arXiv:2509.18237 [astro-ph.HE]

work page arXiv 2025
[23]

Koteraet al.(GRAND, Beacon), The Hybrid Elevated Radio Observatory for Neutrinos (HERON) Project, PoSICRC2025, 1078 (2025), arXiv:2507.04382 [astro- ph.IM]

K. Koteraet al.(GRAND, Beacon), The Hybrid Elevated Radio Observatory for Neutrinos (HERON) Project, PoSICRC2025, 1078 (2025), arXiv:2507.04382 [astro- ph.IM]

work page arXiv 2025
[24]

Asymptotic formulae for likelihood-based tests of new physics

G. Cowan, K. Cranmer, E. Gross, and O. Vitells, Asymp- totic formulae for likelihood-based tests of new physics, Eur. Phys. J. C71, 1554 (2011), [Erratum: Eur.Phys.J.C 73, 2501 (2013)], arXiv:1007.1727 [physics.data-an]. 6 𝜓tol [circ] 0 5 1 0 Significance [𝜎] 0 5 10 15 𝜖= 10% q = 1.0 𝜖 = 33% q= 0.2 𝜖 = 50% q= 𝜖 FIG. 5.Significance versusψ tol for quality ...

work page internal anchor Pith review arXiv 2011