arxiv: 2605.06428 · v1 · submitted 2026-05-07 · 🌌 astro-ph.IM

Recognition: unknown

Muon Track Reconstruction Procedures at the Baikal-GVD Neutrino Telescope

Grigory Safronov

Pith reviewed 2026-05-08 05:00 UTC · model grok-4.3

classification 🌌 astro-ph.IM

keywords Baikal-GVDneutrino telescopemuon track reconstructionneutrino directiontrack-like eventsevent selectiondata analysis pipeline

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The pith

Baikal-GVD reconstructs neutrino arrival directions to 0.2 degree precision from muon tracks produced in nearby interactions.

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

The paper describes procedures developed for the Baikal-GVD neutrino telescope to analyze track-like signals left by muons that originate from neutrino interactions near the detector. These procedures include algorithms for reconstructing the direction and energy of such tracks along with criteria for selecting neutrino candidate events. The work applies an analysis pipeline built from these methods to real data collected during the 2019-2021 seasons and presents preliminary outcomes. A sympathetic reader cares because successful track reconstruction turns the detector into a tool that can point back toward the origins of high-energy cosmic neutrinos with useful angular accuracy.

Core claim

Muons produced in neutrino interactions in the vicinity of the detector leave track-like responses that permit reconstruction of the neutrino arrival direction with a precision up to 0.2 degree. The collaboration has developed a variety of methods for track-like event direction and energy reconstruction together with neutrino candidate event selection; these methods form an analysis pipeline whose application to 2019-2021 data is shown.

What carries the argument

Track-like event analysis methods that process the detector's response to muon tracks, including direction and energy reconstruction algorithms and neutrino candidate selection criteria.

If this is right

The detector can identify and characterize individual neutrino events with directional accuracy sufficient to associate them with distant astrophysical sources.
The analysis pipeline produces usable results on actual recorded data rather than only on simulated events.
Multiple complementary reconstruction techniques can be run in parallel to improve overall event selection efficiency.

Where Pith is reading between the lines

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

Combining the reported angular resolution with the telescope's location could help cross-check neutrino alerts from southern-hemisphere instruments.
If the energy reconstruction component scales reliably, the same tracks could constrain the spectrum of incoming neutrinos without requiring separate calorimetric methods.
Routine application of these procedures to future data-taking seasons would allow statistical studies of neutrino arrival directions over time.

Load-bearing premise

The developed methods for track-like event direction and energy reconstruction and neutrino candidate event selection remain effective and accurate when applied to real data.

What would settle it

Reconstructed directions from the 2019-2021 dataset fail to achieve 0.2-degree resolution when compared against Monte Carlo simulations of known muon tracks or against any coincident events from other instruments.

Figures

Figures reproduced from arXiv: 2605.06428 by Grigory Safronov.

**Figure 5.** Figure 5: Distributions of boosted decision tree classifiers response for low-energy BDT classifier (a) and high-energy classifier (b) for events reconstructed in the data from seasons 2019-2021 compared to signal and background MC expectations view at source ↗

**Figure 1.** Figure 1: FIG. 1: The Baikal-GVD neutrino telescope in the configuration deployed in February - view at source ↗

**Figure 2.** Figure 2: FIG. 2: Precision of muon direction reconstruction as a function of track length. view at source ↗

**Figure 3.** Figure 3: FIG. 3: Muon energy measurement bias and uncertainty as a function of reconstructed view at source ↗

**Figure 4.** Figure 4: FIG. 4: Angular distribution of tracks for the region of zenith angles view at source ↗

**Figure 5.** Figure 5: FIG. 5: Distributions of boosted decision tree classifiers response for low-energy BDT view at source ↗

**Figure 6.** Figure 6: FIG. 6: Distributions of number of track hits (a) and reconstructed muon energy (b) view at source ↗

read the original abstract

The Baikal-GVD neutrino telescope is the largest neutrino detector of its kind in the Northern Hemisphere. Muons produced in neutrino interaction in the vicinity of the detector leave track-like response in the detector allowing to reconstruct the neutrino arrival direction with the precision up to 0.2 degree. The Baikal-GVD collaboration has developed a variety of methods for the track-like event analysis. Methods for track-like event direction and energy reconstruction and neutrino cadidate event selection are discussed in this report. Preliminary results of application of analysis pipeline to the data-taking seasons from 2019 to 2021 are shown.

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

This is a methods report on Baikal-GVD muon track reconstruction with preliminary 2019-2021 data application, but the 0.2° precision claim rests on thin public validation.

read the letter

The paper describes a set of procedures the Baikal-GVD team uses to reconstruct muon tracks from neutrino interactions, covering direction and energy estimation plus candidate selection. It applies the pipeline to real data from 2019-2021 and states an angular resolution reaching 0.2 degrees. That is the core content: detector-specific implementation details rather than a new algorithm or first-principles derivation. The work is useful internally because it documents what the collaboration actually runs on their data and shows that the chain produces results on live runs. Reporting real-data application is a positive step that many similar papers skip. The variety of methods mentioned suggests they have tested several approaches for robustness, which is practical for a large underwater array. The main limitation is the lack of visible quantitative support for the precision figure. No equations, resolution curves, or comparison metrics appear in the summary, so it is difficult to judge whether the 0.2° number holds after accounting for systematics or background. If the full text contains only qualitative statements or unshown simulation studies, the claim stays hard to evaluate independently. The paper does not engage deeply with prior work from IceCube or ANTARES on similar reconstruction problems, which leaves the incremental gain unclear. This is the kind of document that belongs in the collaboration's internal notes or a conference proceedings rather than a high-impact journal. Readers already working on Baikal-GVD or building comparable detectors will find the procedural details worth skimming. Outsiders looking for general advances in track fitting will get little new. It is coherent on its own terms and shows honest engagement with the experiment's data, so it clears the bar for serious refereeing even if the evidence needs strengthening. I would send it to review with a request for explicit validation plots and error budgets.

Referee Report

1 major / 1 minor

Summary. The manuscript describes a variety of methods for track-like event direction and energy reconstruction and neutrino candidate event selection at the Baikal-GVD neutrino telescope. Preliminary results from the application of the analysis pipeline to 2019-2021 data are shown, claiming a reconstruction precision of up to 0.2 degrees for the neutrino arrival direction.

Significance. If the results hold, the paper contributes to neutrino telescope data analysis by detailing multiple reconstruction approaches for a major Northern Hemisphere detector and showing their performance on real data. This is important for advancing the field and for future analyses.

major comments (1)

[Preliminary results] The 0.2 degree precision claim lacks accompanying quantitative validation, such as resolution distributions, pull plots, or comparison to expected performance from simulations, which is necessary to substantiate the central claim about the effectiveness of the methods on real data.

minor comments (1)

[Abstract] Typo: 'cadidate' should be 'candidate'.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the careful review and constructive comments on our manuscript describing muon track reconstruction procedures at Baikal-GVD. We address the major comment point by point below and will incorporate revisions to strengthen the presentation of our preliminary results.

read point-by-point responses

Referee: [Preliminary results] The 0.2 degree precision claim lacks accompanying quantitative validation, such as resolution distributions, pull plots, or comparison to expected performance from simulations, which is necessary to substantiate the central claim about the effectiveness of the methods on real data.

Authors: We agree that the current manuscript version would benefit from additional quantitative validation to support the stated reconstruction precision of up to 0.2 degrees. In the revised version, we will include angular resolution distributions obtained from Monte Carlo simulations for the track reconstruction methods, pull plots for the direction and energy estimators where relevant, and direct comparisons of the observed performance on the 2019-2021 data with the expected simulation results. These additions will provide the necessary substantiation for the effectiveness of the analysis pipeline on real data. revision: yes

Circularity Check

0 steps flagged

No significant circularity detected

full rationale

The paper reports developed reconstruction procedures for muon tracks in the Baikal-GVD detector and presents preliminary applications to 2019-2021 real data. No load-bearing derivations, predictions, or equations are described that reduce by construction to fitted inputs, self-definitions, or self-citation chains. The 0.2° angular resolution is presented as the achieved outcome of the methods rather than an input assumption, and the text focuses on procedural descriptions and data results without internal circular reductions. This is a standard methods-and-results report with independent external data validation.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

No free parameters, axioms, or invented entities are identifiable from the abstract, which focuses on high-level description of reconstruction procedures without technical details.

pith-pipeline@v0.9.0 · 5388 in / 1002 out tokens · 23330 ms · 2026-05-08T05:00:28.170969+00:00 · methodology

discussion (0)

Reference graph

Works this paper leans on

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INTRODUCTION The main purpose of the large-volume neutrino telescopes such as Baikal-GVD is the study of TeV – PeV cosmic neutrino flux. The Baikal-GVD telescope being constructed in Lake Baikal presently consists of 14 independent sub-detectors - clusters, carrying in total 4212 optical modules enabling the detection volume in high-energy cascade detecti...

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THE BAIKAL-GVD NEUTRINO TELESCOPE The Baikal-GVD neutrino telescope in its present configuration consists of 14 independent sub-detectors – clusters (Fig. 1). The detector volume of>0.6 km 3 makes it the largest neutrino telescope in the Northern Hemisphere. The lake depth at the telescope location is about 1366 meters, water light absorption length reach...
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The backround is due to luminiscense in layers of sinking remains of living organisms and/or algae

MUON TRACK RECONSTRUCTION The dominant source of PMT pulses (or hits) in the telescope data is the ambient optical background of the Lake Baikal waters. The backround is due to luminiscense in layers of sinking remains of living organisms and/or algae. The PMT signal due to background is at the 1 photoelectron level. The rate is not uniform and depends on...
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Reconstructed events are dominated by muon bundles and the total rate of events passing the reconstruction procedure is∼3 Hz per cluster

NEUTRINO CANDIDA TE EVENT SELECTION The described track reconstruction procedure was applied to the data and MC of data- taking seasons 2019–2021 in the single cluster-regime. Reconstructed events are dominated by muon bundles and the total rate of events passing the reconstruction procedure is∼3 Hz per cluster. In this analysis the region of interest for...

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RESUL TS OF THE DA T A PROCESSING An event selection procedure was applied to the data sample of data-taking seasons 2019–2021. The total livetime of the sample corresponds to the 14.4 years of data -taking in single-cluster regime. An event sample of 1189 neutrino candidates was selected with the aforementioned cuts on the BDT classifiers response. An ev...

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Reconstruction algorithms allows to reconstruct the muon direction with the precision up to 0.2 ◦ for track of>500 m length

SUMMAR Y Methods and procedures for the track-like events reconstruction at the Baikal-GVD neu- trino telescope were discussed. Reconstruction algorithms allows to reconstruct the muon direction with the precision up to 0.2 ◦ for track of>500 m length. The muon energy is reconstructed with the precision of the factor 2.5. Misreconstructed atmospheric muon...

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