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Search for Quantum Decoherence with 10.7 years of atmospheric $\nu_\mu$ events in IceCube

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ReviewThe objections and verdict, as JSON Paper breakdownThe authors' claims, conditions and measurements, as JSON Signed receiptProof this review has not been altered
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Tanvi Krishnan (for the IceCube Collaboration)

High Energy Astrophysical Phenomena · Submitted 16 Jul 2025 · 10 references

Pith's verdict: A plausible but numbers-light proceedings update from IceCube: improved sensitivity for quantum decoherence is likely real, yet the Asimov calibration and missing quantitative values leave the main claim under-supported.

T0 · AI review

How this review was made: An AI referee (deepseek-v4-flash) read the paper on August 6, 2026 and answered a fixed list of questions about it. T0 is the starting level every paper gets. The levels describe how deeply Pith has checked the paper, never the authors.

  1. T0 AI review An AI read the paper and answered a fixed list of questions.
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  3. T2 Compute The paper's code or calculations re-run with the same results.
  4. T3 Formal statement The claims written out in a formal math language a computer can read.
  5. T4 Proof Those claims proved, and the proof checked by computer.

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arXiv ID2507.12316 (version 1)
Pith IDEIIHM2HM, Pith's permanent record of this paper and its review
CitationTanvi Krishnan (for the IceCube Collaboration). "Search for Quantum Decoherence with 10.7 years of atmospheric $\nu_\mu$ events in IceCube." arXiv:2507.12316 (2025). https://pith.science/paper/EIIHM2HM
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The paper

The paper claims

Ten years of neutrino telescope data are projected to give the world's most sensitive search for quantum decoherence.

The reading

The paper claims that a search for quantum decoherence using 10.7 years of upward-going atmospheric muon neutrinos from a cubic-kilometre South Pole neutrino telescope would achieve world-leading sensitivity, markedly better than the collaboration's own previous 7.6-year result. If real, this means the analysis can set the tightest constraints yet on the idea that Planck-scale fluctuations of spacetime make neutrinos lose quantum coherence as they travel. The improvement comes from a larger event sample, higher event purity, an upgraded selection, and a fuller treatment of systematic uncertainties, all folded into an Asimov sensitivity calculation. The work matters because neutrino oscillations act as a natural long-baseline interferometer for probing the quantum nature of gravity.

What carries the argument

The analysis is carried by the Lindblad master equation for open quantum systems, $\dot{\rho} = -i[H,\rho] - D[\rho]$, where the decoherence superoperator $D$ is expanded in the Gell-Mann basis and taken diagonal, parameterized by a single strength $\Gamma_0$ with power-law energy dependence $\Gamma(E) = \Gamma_0 (E/E_0)^n$. Two models are defined by the pattern of zeros in $D$: state selection, $\mathrm{diag}(0,\Gamma,\dots,\Gamma)$, drives the flux toward an equal mixture of flavors, while phase perturbation, $\mathrm{diag}(0,\Gamma,\Gamma,0,\Gamma,\Gamma,\Gamma,\Gamma,0)$, drives it toward an incoherent sum of mass states. On the data side, a likelihood test statistic with continuous nuisance parameters for fluxes, ice properties, detector response, and attenuation, binned in reconstructed muon energy and zenith angle, with starting and throughgoing events fit separately, converts the predicted oscillogram distortions into a projected confidence interval on $\Gamma_0$.

Extended reading notes

Core claim

The central claim is that the updated analysis, using 368,071 up-going muon neutrino events with reconstructed energies from 0.5 to 100 TeV, has projected sensitivity to the decoherence parameter $\Gamma_0$ that is greatly improved compared with the prior analysis for each energy-dependence exponent $n = 0, 1, 2, 3$ and for both interaction models considered (democratic state selection and mass-state phase perturbation). The paper presents this as an expected sensitivity from an Asimov dataset, not as a measurement; after verifying the expected sensitivity with simulations, the collaboration is proceeding to unblind the data. If the projection holds, this becomes the world-leading search for quantum decoherence of neutrinos.

Load-bearing premise

The projected sensitivity assumes the Monte Carlo simulations and the modelled systematic uncertainties (neutrino fluxes, ice properties, detector response, and attenuation) faithfully describe the real 10.7 years of data, so the Asimov curves will match what an unblinded fit actually finds.

Editorial extensions

If this is right

  • If the projected sensitivity holds on unblinded data, the experiment would set the tightest experimental constraints on neutrino decoherence induced by Planck-scale spacetime fluctuations, improving on its own previous world-leading limit.
  • For each energy exponent $n = 0, 1, 2, 3$ and both interaction models, the analysis yields an expected 90% confidence interval on $\Gamma_0$ that is visibly narrower than the previous result's sensitivity and upper limit.
  • The higher event purity (99.9% versus 99%) and the separation of starting and throughgoing events make the analysis less dependent on background assumptions, so the resulting limits would be more robust to a wider class of systematic variations.
  • Because the same event selection is already in use for other oscillation-based searches, the improved sensitivity transfers directly to those analyses as well.

Reading between the lines

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

  • If no signal appears, the null result would begin to close off the simplest virtual-black-hole models of quantum gravity, where the decoherence rate is set by the Planck scale with little or no energy suppression ($n$ near zero).
  • The two models predict different long-distance flavor mixtures (equal flavors versus incoherent mass states), so a positive signal could in principle be used to distinguish them, given the added energy and angle coverage from the starting/throughgoing split.
  • A real detection would likely look like a suppression of the standard oscillation pattern at high energies and near-horizontal directions; because this mimics other new-physics signatures such as sterile neutrinos, the two searches should be cross-checked against each other rather than interpreted independently.
Original abstract

In order to develop a consistent quantum theory of gravity, we must understand the nature of spacetime at the Planck scale. In particular if it exhibits quantum fluctuations, they may cause propagating particles to evolve in an apparently non-unitary manner. Neutrinos, which interact only via the weak force and gravity, maintain quantum coherence while propagating over large distances. Thus, neutrino oscillations serve as a precise interferometer to search for Planck-scale fluctuations of spacetime. The IceCube Neutrino Observatory is the world's largest neutrino telescope, located in the Antarctic icecap. We search the data on atmospheric neutrinos detected by IceCube in the energy range 0.5-100 TeV to test for neutrino decoherence. In this contribution, we present the sensitivity of the analysis, which shows significant improvement compared to previous IceCube results as a result of improved reconstruction and a larger sample of events.

The compiled record

The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.

Compiled by classifier-1.13.0 via TypeSafe API, question bank abstract-p1-20260923, 2026-09-23: 1 request, 5,576 input tokens.

What the abstract itself states, as probabilities: claims first 0.04 · states limitation 0.11 · human participants 0.02 · controlled comparison 0.19 · randomized assignment 0.01 · states quantitative result 0.12 · compares with prior results 0.92 · mentions code or data availability 0.02.

The abstract, sentence by sentence

arXiv listing abstract v1. Results and the main claim are underlined; .

In order to develop a consistent quantum theory of gravity, we must understand the nature of spacetime at the Planck scale. In particular if it exhibits quantum fluctuations, they may cause propagating particles to evolve in an apparently non-unitary manner. Neutrinos, which interact only via the weak force and gravity, maintain quantum coherence while propagating over large distances. Thus, neutrino oscillations serve as a precise interferometer to search for Planck-scale fluctuations of spacetime. The IceCube Neutrino Observatory is the world's largest neutrino telescope, located in the Antarctic icecap. We search the data on atmospheric neutrinos detected by IceCube in the energy range 0.5-100 TeV to test for neutrino decoherence. In this contribution, we present the sensitivity of the analysis, which shows significant improvement compared to previous IceCube results as a result of improved reconstruction and a larger sample of events.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#sentencerolethe authors' own workstates the main conclusionstrength
s0 In order to develop a consistent quantum theory of gravity, we must understand the nature of spacetime at the Planck scale. background 1.00 0.03 0.02 asserted 0.97
s1 In particular if it exhibits quantum fluctuations, they may cause propagating particles to evolve in an apparently non-unitary manner. background 1.00 0.04 0.02 hedged possibility 1.00
s2 Neutrinos, which interact only via the weak force and gravity, maintain quantum coherence while propagating over large distances. background 1.00 0.06 0.03 asserted 1.00
s3 Thus, neutrino oscillations serve as a precise interferometer to search for Planck-scale fluctuations of spacetime. background 0.91 0.07 0.05 asserted 0.99
s4 The IceCube Neutrino Observatory is the world's largest neutrino telescope, located in the Antarctic icecap. background 0.75 0.05 0.02 asserted 1.00
s5 We search the data on atmospheric neutrinos detected by IceCube in the energy range 0.5-100 TeV to test for neutrino decoherence. method 0.74 0.94 0.05 asserted 0.86
s6 In this contribution, we present the sensitivity of the analysis, which shows significant improvement compared to previous IceCube results as a result of improved reconstruction and a larger sample of events. contribution 0.60 0.94 0.39 asserted 1.00

What kind of paper the classifier reports this is: empirical study 1.00 · evidence from analysis of existing data 0.94.

What was examined, and what was not

sources read
  • arXiv listing abstract v1
not examined
  • full text
  • figures and tables
  • references and citing sentences
  • relations to other papers
levels run
  • P abstract
not run
  • S sections
  • T body sentences
  • C citations
  • R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

Figures
Figure 1. Decoherence of an oscillating neutrino ensemble. The emergence of non-unitary behavior from various types of interactions between neutrinos and VBHs. The top two rows correspond to the state selection model where the neutrino wavefunction is collapsed into a democratically selected flavor or mass eigenstate. The bottom row corresponds to the phase perturbation model, where the neutrino wavefunction’s phase in the mass basis is perturbed. Taken from [2] where 𝜌 𝜈 are the coefficients of the system’s density matrix expanded in the basis of 𝑏 𝜇 . The matrix 𝐷𝜇𝜈 is an 9 × 9 matrix that
Figure 2. Muon neutrino oscillogram. Ratio of the predicted 𝜈𝜇 flux for the state selection model with the decoherence parameters listed compared to the standard model prediction. 4. Event Selection and Systematic Uncertainties This analysis constrains 𝜈VBH models with 10.7 years of IceCube data using 368, 071 up-going 𝜈𝜇 events with reconstructed energies ranging from 0.5 to 100 TeV. The updated event selection is described in detail in [7] and has been used by the IceCube collaboration for searches for eV-scale sterile neutrinos, and other searches currently in progress. The 𝜈VBH…
Figure 3. Sensitivities of the old (dashed) [2] and new (solid) analyses for both models: phase perturbation (top) and state selection (bottom). The prior analysis’s upper limit is also shown (dotted). The sensitivity has greatly improved since the last iteration of the analysis. 6. Conclusions An updated quantum decoherence analysis using improved systematic treatment and 10.7 years of upward-going muon neutrino events has been presented. This analysis has world-leading sensitivity to quantum decoherence. Having verified the expected sensitivity using simulations, we are now proceeding…

Figures reproduced from arXiv:2507.12316 by the authors.

References

Discussion

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