Pith. sign in

REVIEW 2 major objections 4 minor 108 references

The pure qubit–qubit–qutrit spin state produced in the three-body Higgs decay h→τ−τ+Z is genuinely tripartite-entangled over almost all of phase space, violates the tight 4×4×2 Bell inequalities everywhere, and carries non-local magic peaki

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗

T0 review · deepseek-v4-flash

2026-08-01 00:41 UTC pith:KSHMVDTR

load-bearing objection Genuinely new analytic results on 2x2x3 Bell inequalities and asymmetric magic in a collider decay; the numerical optimization for non-local magic is the one quantitative claim that needs support before I'd trust the headline numbers. the 2 major comments →

arxiv 2607.26122 v1 pith:KSHMVDTR submitted 2026-07-28 quant-ph hep-exhep-ph

Qubit-qubit-qutrit quantum correlations in H to f bar f V

Micha{\l} Banacki , Misaki Ohta , Abhyoudai S. Shaleena , Pawe{\l} Caban , Micha{\l} Eckstein , Kazuki Sakurai , Michael Spannowsky , Pawe{\l} Horodecki This is my paper
classification quant-ph hep-exhep-ph
keywords Higgs decaytripartite entanglementqubit-qubit-qutritBell inequalitynon-local magicstabiliser Rényi entropyhyperdeterminanttau-Z spin correlations
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

Three-body Higgs decays into a tau pair and a Z boson produce a pure spin state with two qubits and one qutrit. The paper shows that this state is nonclassical everywhere: it is genuinely 2⊗2⊗3 entangled over almost the whole phase space, it violates the tight 4×4×2 Bell inequalities at every point (from ≈5.6 at threshold to ≈7.9 near the di-tau endpoint, against an LHV bound of 4 and quantum bound 8), and it carries non-local magic that peaks at log2(27/7)≈1.95 exactly where the tripartite entanglement is largest. The analysis is made possible by expanding the tree-level amplitude in the small fermion mass, which exposes a pointer-state structure and yields compact closed formulas for every observable. Two results are new: a semi-analytic optimisation of the tight 4×4×2 Bell inequalities for any 2⊗2⊗d system, and an extension of the stabiliser Rényi entropy and non-local magic to systems with unequal local dimensions. If the claims hold, h→τ−τ+Z becomes a practical laboratory for genuine three-party quantum correlations, and the differential decay rate is shown to concentrate precisely in the most nonclassical region.

Core claim

On the paper's own terms, the central discovery is that the spin state produced in H→f fbar V, specialised to h→τ−τ+Z, is a pure state whose nonclassicality is controlled by a tiny mass parameter ε. At leading order the state is a GHZ-like superposition of two branches in which the fermion helicities are correlated with two vector-boson pointer states; the overlap of the pointer states governs where entanglement lives. The genuinely tripartite 2⊗2⊗3 character is switched on at O(ε), detected by the minors and hyperdeterminant of the 3×4 amplitude matrix, and the state belongs to the generic class over essentially the whole plane except along nodal curves and at the di-tau threshold. The tigh

What carries the argument

The argument is carried by four pieces. (1) The ε-expansion of the tree-level amplitude around the massless-fermion limit, where the zeroth-order state is a superposition of two pointer states tagged by fermion helicities and the sub-leading corrections occupy the same-helicity subspace; this expansion makes every observable a compact formula in each corner of phase space. (2) The hyperdeterminant M=m1m4−m2m3 of the amplitude matrix together with the local ranks, which separates the SLOCC classes and detects genuine 2⊗2⊗3 entanglement; the leading minors are O(ε), and their zeros define nodal curves governed by the vector-to-axial coupling ratio. (3) For Bell inequalities: a reduction of the

Load-bearing premise

The reported phase-space maxima of the Bell observables and of non-local magic rely on numerical optimisation (an 8-parameter search for the qutrit measurements and a 14-parameter search over local unitaries) rather than a certified global method; if the true extrema differ, the quantitative values could shift, although the Bell violation itself is robust because the minimum analytic value ≈5.6 is far above the bound 4.

What would settle it

Reconstruct the spin density matrix of h→τ−τ+Z in an event sample and evaluate the three optimised Bell observables B_442, B'_424, B'_244; finding any phase-space point with a value below 4 would refute the universality claim, and finding a value above the predicted ≈7.9 near the endpoint would signal a defect in the amplitude. Alternatively, run a certified global optimisation of the qutrit projectors at a fixed phase-space point and check whether the value exceeds the reported maximum.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • Because the Bell violation is everywhere at least ≈5.6, with the endpoint within a few percent of the quantum bound 8, even a modest, non-exhaustive scan of settings certifies tripartite nonlocality in this decay.
  • The differential decay rate is concentrated in the near-endpoint region, where the state approaches the generalised GHZ form and the non-local magic sits on its plateau; most produced events are therefore the most nonclassical ones.
  • The maxima of genuine tripartite entanglement and non-local magic occur at the same point (collinear kinematics, m_ττ≈12 GeV), so one observable can be used to locate the other.
  • The monogamy-like trade-off between the fermion-pair concurrence and the fermion–boson entanglement means that an apparent suppression of di-tau entanglement is not a loss of quantumness but a transfer to fermion–boson pairs.
  • The new semi-analytic Bell optimisation and the unequal-dimension stabiliser Rényi entropy apply to any 2⊗2⊗d state and to arbitrary collections of prime-dimensional subsystems, not just this decay.

Where Pith is reading between the lines

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

  • If the predicted non-local magic is confirmed, the 'one bit from dimensional mismatch' phenomenon suggests a general resource: embedding a two-qubit stabiliser GHZ state in a higher-dimensional local space creates magic without changing the entanglement spectrum, which could be exploited in other settings where one party has a natural three-level structure.
  • The numerical global-extrema assumption is the soft spot; a certified global optimisation or analytic closed form for the qutrit projectors would be a clean follow-up. Even if the quoted maxima shift by a few percent, the minimum analytic bound ≈5.6 keeps the Bell violation robust.
  • The location of the minor nodal curves is set by c_V/c_A; since radiative corrections shift it only by a few percent, the angular pattern of genuine tripartite entanglement is effectively a tree-level probe of the vector-to-axial coupling ratio, potentially usable as a new physics discriminant.
  • The authors' rough yield estimates (of order 10^3–10^4 leptonically tagged events at a high-luminosity hadron collider) suggest that a first measurement of three-party correlations in this channel is within reach; a dedicated detector-level study with tau spin-analysing power would be the natural test.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

2 major / 4 minor

Summary. The paper studies the pure three-partite spin state produced in H -> f fbar V, specializing to h -> tau^- tau^+ Z, and maps its quantum correlations across phase space. Working at tree level with a systematic expansion in the fermion mass, it obtains compact analytic formulas for bipartite and genuine 2⊗2⊗3 entanglement, for the maximized 4×4×2 Bell operators, and for a new extension of the stabilizer Rényi entropy and non-local magic to unequal local dimensions. The central claims are that the state is genuinely 2⊗2⊗3 entangled over almost all phase space, that all three tight Bell inequalities are violated everywhere (reaching near the quantum bound at the upper endpoint), and that the non-local magic is approximately one bit at the endpoint and peaks at log2(27/7) ≈ 1.95 in collinear regions, with the differential decay rate concentrated in the most nonclassical region.

Significance. If the results hold, the paper makes two genuinely useful contributions: a semi-analytic treatment of tight 4×4×2 Bell inequalities for 2⊗2⊗d systems, and a systematic definition of non-local magic for unequal local dimensions, applied to a physically realistic and analytically tractable collider process. The derivation is self-contained and parameter-free: the spin state is computed from first principles, and the compact formulas are checked against the numerical maps in kinematic limits. The identification of the pointer-state structure, the CP-imposed mirror symmetries, and the monogamy-like trade-offs are valuable. The main weakness is numerical certification: the non-local magic is defined through a 14-parameter minimization and the headline values rely on repeated local searches, so the reported numbers are not proven global extrema. This affects the quantitative claims but not the robust qualitative conclusions such as Bell violation and the presence of magic.

major comments (2)
  1. [Sec. 5.2 / Eq. (5.12)] The non-local magic is defined as a minimum over a 14-parameter local-unitary manifold and computed with repeated local searches. For a minimization, a local search yields an upper bound on M_nl, not a certified value; a missed local-unitary basis would lower M_nl below the reported values. The saturation claims underlying the two headline results -- the endpoint value 'almost exactly one bit' (Eq. (5.15): 'we have verified numerically') and M_nl(kappa)=M_2(kappa) along the collinear family with peak log2(27/7) (Eqs. (5.16)-(5.17): 'we find numerically') -- are not backed by a certificate, an analytic proof, or released code. Since these values are central to the abstract and conclusions, this is load-bearing. Please provide an analytic proof of the saturation claims, a certified global optimization, or make the numerical code, seeds, and convergence criteria available; otherwise the qua
  2. [Sec. 4.1/4.2, Eqs. (4.8), (4.19)] The Bell-inequality maxima are obtained after analytic reduction to residual searches over 8 (B_442) and 9 (B'_424) parameters, which are then optimized by local searches. This does not invalidate the core violation claim: the reported values exceed the LHV bound 4 everywhere, and the threshold value 4*sqrt(1+C_AB^2) ≈ 5.6 is analytic, so even an underestimated maximum would leave the violation intact. However, the quantitative statements 'within a few per cent of the quantum bound' and the 0.01-level differences shown in Fig. 10 depend on convergence of these local searches. The manuscript should specify the number of restarts, stopping criteria, and ideally provide the code or data for the residual optimizations so that the maps are reproducible.
minor comments (4)
  1. [Fig. 10 caption] The caption admits 'numerical artefacts' in the pairwise Bell differences. With a claimed semi-analytic optimization, such artefacts should be eliminated or explained; otherwise they undermine confidence in the 0.01-level quantitative comparisons.
  2. [Sec. 5.1] The paper correctly notes that monotonicity of the stabilizer Rényi entropy has not been established for mixed local dimensions. Since the term 'non-local magic' carries resource-theoretic connotations, please state explicitly which properties of M_nl are proven and that monotonicity is not needed for the present physical conclusions.
  3. [Abstract / Sec. 6] The phrase 'most nonclassical region' is ambiguous: the Bell violation is maximal near the endpoint, whereas M_nl peaks in the collinear hot-spot region, which is rate-suppressed. Please specify which resource is meant, or qualify the statement.
  4. [References] Reference [113] (HL-LHC technical design report) lacks volume/publisher/DOI information; please provide the full citation.

Circularity Check

0 steps flagged

Self-contained derivation from explicit tree-level amplitudes; no circularity found.

full rationale

The derivation chain is self-contained: the spin state (Eqs. (2.14)–(2.25)) is computed from explicit tree-level Feynman amplitudes with Standard Model couplings, containing no parameters fitted to the target observables. The entanglement measures (Sec. 3), Bell maxima (Eqs. (4.8), (4.19), (4.23)), and magic quantities (Eqs. (5.9), (5.12), (5.15)–(5.17)) are all evaluated directly from this state or derived analytically in the phase-space limits. No fitted input is renamed as a prediction, and no equation reduces to its own input by construction. The self-citations (e.g., Ref. [83] for the three-qubit optimisation framework) are not load-bearing: the relevant optimisation is re-derived in the text, while the tightness and LHV-bound facts are cited to external works [100,101]. The numerical saturation claims for M_nl rest on repeated local searches and are honestly presented as such, including acknowledged limitations such as the unproven monotonicity of SRE for unequal local dimensions and isolated numerical artefacts; these are optimisation/robustness caveats, not circularity. The paper is therefore assessed as non-circular.

Axiom & Free-Parameter Ledger

0 free parameters · 6 axioms · 0 invented entities

No free parameters are fitted: all inputs are Standard Model masses and couplings (mτ, mZ, mh, sin^2θW) and the derived expansion parameter ε. The calculation rests on tree-level SM amplitudes, the purity of the final spin state, and the validity of the small-m_f expansion. No new particles or entities are introduced. The numerical global-optimization assumption is the least-supported step.

axioms (6)
  • domain assumption The effective Lagrangian in Eq. (2.5) (g_Hff, g_HVV, g_Vff with chiral couplings) is the complete interaction for H→f bar f V at tree level.
    The spin state (2.13) is computed from these amplitudes only; BSM contributions would alter all results. Sec. 2.2.
  • domain assumption The final-state spin state is pure: |ψ> ∝ Σ M_{h_A,h_B,h_V} |h_A,h_B,h_V>, with no entanglement with momentum or radiation degrees of freedom.
    Purity is used throughout (I-concurrence, SRE, Miyake classification). Radiation decoherence is discussed but not included. Sec. 2.2 and Sec. 6.
  • domain assumption CP is conserved by the effective interactions, leading to the phase-free CP relation (2.34).
    This symmetry is used to relate observables at θ and π−θ across all sections. Sec. 2.3.
  • domain assumption The fermion-mass expansion (2.14) with ε ≈ 0.03 is valid and the O(ε) truncation captures the genuine 2⊗2⊗3 structure.
    The paper argues the hierarchy persists at loop level but does not prove it to all orders. Used to derive limiting formulas. Sec. 2.2 and Sec. 3.2.
  • domain assumption The stabilizer Rényi entropy definitions and properties (i)–(iv) extend to composite systems with unequal prime local dimensions.
    Used to define magic for the 2⊗2⊗3 system. The authors state faithfulness/Clifford invariance/additivity carry over; monotonicity (α≥2) is not established for mixed dimensions (explicitly noted). Sec. 5.1.
  • ad hoc to paper The numerical searches over Bell settings (8-parameter) and local unitaries (14-parameter) reached the global optimum.
    The reported maxima/minima assume global convergence. Paper uses 'repeated local searches' (Sec. 5.2) and shows numerical artefacts (Fig. 10), so this is an unproven computational assumption.

pith-pipeline@v1.3.0-alltime-deepseek · 46897 in / 16105 out tokens · 132206 ms · 2026-08-01T00:41:52.079670+00:00 · methodology

0 comments
read the original abstract

We perform an extensive analysis of the quantum correlations carried by the qubit-qubit-qutrit pure state arising in the decay of a massive scalar into a fermion-antifermion pair and a massive gauge boson, $H \to f \bar f V$, specialising to the Higgs boson decay $h \to \tau^- \tau^+ Z$. Working with the exact tree-level spin state and its systematic expansion around the massless-fermion limit, we obtain analytic control over the entire phase space: the bipartite entanglement measures, the genuine $2 \otimes 2 \otimes 3$ entanglement structure (the Miyake classification), as well as the Bell-inequality violations and the non-stabiliserness (magic) are all mapped and reproduced by compact formulas. The bipartite measures exhibit a monogamy-like trade-off between the fermion pair and the fermion-boson pairs. The state is genuinely $2 \otimes 2 \otimes 3$ entangled over almost the entire phase space, most strongly in the collinear regions. We derive, for the first time, semi-analytical expressions for the tight $4 \times 4 \times 2$ Bell inequalities of the $2 \otimes 2 \otimes 3$ system, generalising the optimisation previously available only for three qubits, and find that the local-hidden-variable bound is violated over the entire phase space, reaching within a few per cent of the quantum bound at the upper endpoint of the di-tau mass spectrum. We further extend the stabiliser R\'enyi entropy and the non-local magic to systems with unequal local dimensions, and show that the near-endpoint state carries almost exactly one bit of non-local magic, which peaks at $\log_2 \frac{27}{7} \simeq 1.95$ in the collinear regions. The differential decay rate concentrates precisely in the most nonclassical region of the phase space.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

108 extracted references · 77 linked inside Pith

  1. [1]

    Afik and J.R.M.n

    Y. Afik and J.R.M.n. de Nova,Entanglement and quantum tomography with top quarks at the LHC,Eur. Phys. J. Plus136(2021) 907 [2003.02280]

    Pith/arXiv arXiv 2021

  2. [2]

    Fabbrichesi, R

    M. Fabbrichesi, R. Floreanini and G. Panizzo,Testing Bell Inequalities at the LHC with Top-Quark Pairs,Phys. Rev. Lett.127(2021) 161801 [2102.11883]

    Pith/arXiv arXiv 2021

  3. [3]

    Severi, C.D.E

    C. Severi, C.D.E. Boschi, F. Maltoni and M. Sioli,Quantum tops at the LHC: from entanglement to Bell inequalities,Eur. Phys. J. C82(2022) 285 [2110.10112]

    Pith/arXiv arXiv 2022

  4. [4]

    Aoude, E

    R. Aoude, E. Madge, F. Maltoni and L. Mantani,Quantum SMEFT tomography: Top quark pair production at the LHC,Phys. Rev. D106(2022) 055007 [2203.05619]

    Pith/arXiv arXiv 2022

  5. [5]

    Afik and J.R.M

    Y. Afik and J.R.M. de Nova,Quantum information with top quarks in QCD,Quantum6 (2022) 820 [2203.05582]

    Pith/arXiv arXiv 2022

  6. [6]

    Aguilar-Saavedra and J.A

    J.A. Aguilar-Saavedra and J.A. Casas,Improved tests of entanglement and Bell inequalities with LHC tops,Eur. Phys. J. C82(2022) 666 [2205.00542]

    Pith/arXiv arXiv 2022

  7. [7]

    Fabbrichesi, R

    M. Fabbrichesi, R. Floreanini and E. Gabrielli,Constraining new physics in entangled two-qubit systems: top-quark, tau-lepton and photon pairs,Eur. Phys. J. C83(2023) 162 [2208.11723]

    Pith/arXiv arXiv 2023

  8. [8]

    Afik and J.R.M.n

    Y. Afik and J.R.M.n. de Nova,Quantum Discord and Steering in Top Quarks at the LHC, Phys. Rev. Lett.130(2023) 221801 [2209.03969]

    Pith/arXiv arXiv 2023

  9. [9]

    Severi and E

    C. Severi and E. Vryonidou,Quantum entanglement and top spin correlations in SMEFT at higher orders,JHEP01(2023) 148 [2210.09330]

    Pith/arXiv arXiv 2023

  10. [10]

    Z. Dong, D. Gon¸ calves, K. Kong and A. Navarro,Entanglement and Bell inequalities with boostedt t,Phys. Rev. D109(2024) 115023 [2305.07075]

    Pith/arXiv arXiv 2024

  11. [11]

    Aguilar-Saavedra,Postdecay quantum entanglement in top pair production,Phys

    J.A. Aguilar-Saavedra,Postdecay quantum entanglement in top pair production,Phys. Rev. D 108(2023) 076025 [2307.06991]. – 43 –

    Pith/arXiv arXiv 2023

  12. [12]

    T. Han, M. Low and T.A. Wu,Quantum Entanglement and Bell Inequality Violation in Semi-Leptonic Top Decays,2310.17696

    Pith/arXiv arXiv

  13. [13]

    Cheng, T

    K. Cheng, T. Han and M. Low,Optimizing fictitious states for Bell inequality violation in bipartite qubit systems with applications to thet ¯tsystem,Phys. Rev. D109(2024) 116005 [2311.09166]

    Pith/arXiv arXiv 2024

  14. [14]

    Maltoni, C

    F. Maltoni, C. Severi, S. Tentori and E. Vryonidou,Quantum detection of new physics in top-quark pair production at the LHC,JHEP03(2024) 099 [2401.08751]

    Pith/arXiv arXiv 2024

  15. [15]

    Maltoni, C

    F. Maltoni, C. Severi, S. Tentori and E. Vryonidou,Quantum tops at circular lepton colliders, JHEP09(2024) 001 [2404.08049]

    Pith/arXiv arXiv 2024

  16. [16]

    Z. Dong, D. Gon¸ calves, K. Kong, A.J. Larkoski and A. Navarro,Hadronic top quark polarimetry with ParticleNet,Phys. Lett. B862(2025) 139314 [2407.01663]

    Pith/arXiv arXiv 2025

  17. [17]

    Cheng, T

    K. Cheng, T. Han and M. Low,Optimizing entanglement and Bell inequality violation in top antitop events,Phys. Rev. D111(2025) 033004 [2407.01672]

    arXiv 2025

  18. [18]

    T. Han, M. Low, N. McGinnis and S. Su,Measuring Quantum Discord at the LHC, 2412.21158

    Pith/arXiv arXiv

  19. [19]

    Altomonte, A.J

    C. Altomonte, A.J. Barr, M. Eckstein, P. Horodecki and K. Sakurai,Prospects for quantum process tomography at high energies,2412.01892

    Pith/arXiv arXiv

  20. [20]

    Cheng and B

    K. Cheng and B. Yan,Bell Inequality Violation of Light Quarks in Back-to-Back Dihadron Pair Production at Lepton Colliders,2501.03321

    Pith/arXiv arXiv

  21. [21]

    Y. Afik, Y. Kats, J.R.M. de Nova, A. Soffer and D. Uzan,Entanglement and Bell nonlocality with bottom-quark pairs at hadron colliders,Phys. Rev. D111(2025) L111902 [2406.04402]

    Pith/arXiv arXiv 2025

  22. [22]

    Nason, E

    P. Nason, E. Re and L. Rottoli,Spin Correlations int ¯tProduction and Decay at the LHC in QCD Perturbation Theory,2505.00096

    arXiv

  23. [23]

    Fabbrichesi, R

    M. Fabbrichesi, R. Floreanini and L. Marzola,Local vs. nonlocal entanglement in top-quark pairs at the LHC,JHEP11(2025) 005 [2505.02902]

    arXiv 2025

  24. [24]

    Lin, M.-J

    S.-J. Lin, M.-J. Liu, D.Y. Shao and S.-Y. Wei,Spin correlations and Bell nonlocality inΛ Λ pair production from e +e− collisions with a thrust cut,JHEP11(2025) 082 [2507.15387]

    arXiv 2025

  25. [25]

    Low,Addressing local realism through Bell tests at colliders,Phys

    M. Low,Addressing local realism through Bell tests at colliders,Phys. Rev. D112(2025) 096008 [2508.10979]

    arXiv 2025

  26. [26]

    Durupt, F

    V. Durupt, F. Maltoni and O. Mattelaer,Automated computation of spin-density matrices and quantum observables for collider physics,2510.17730

    Pith/arXiv arXiv

  27. [27]

    Gabrielli and L

    E. Gabrielli and L. Marzola,Quantum entanglement and bell nonlocality at future lepton colliders,Eur. Phys. J. Plus141(2026) 331 [2602.03960]

    arXiv 2026

  28. [28]

    Y.-C. Guo, T. Han, M. Low and Y. Su,Quantum Tomography of Fermion Pairs ine +e− Collisions: Longitudinal Beam Polarization Effects,2602.02719

    arXiv

  29. [29]

    Y.-J. Fang, A. Bhoonah, K. Cheng, T. Han, Y. Liu and H. Zhang,Spin Correlation and Quantum Entanglement of Fermion Pairs in Transversely Polarizede −e+ Collisions, 2604.11887. – 44 –

    Pith/arXiv arXiv

  30. [30]

    Choi, D.W

    S.Y. Choi, D.W. Kang, J.S. Lee and C.B. Park,Quantum entanglement and Bell nonlocality in top-quark pair production at a photon linear collider,2603.12830

    arXiv

  31. [31]

    Altakach, P

    M.M. Altakach, P. Lamba, F. Maltoni and K. Sakurai,Quantum properties of heavy-fermion pairs at a lepton collider with polarised beams,2601.09558. [32]ATLAScollaboration,Observation of quantum entanglement with top quarks at the ATLAS detector,Nature633(2024) 542 [2311.07288]. [33]CMScollaboration,Observation of quantum entanglement in top quark pair prod...

    arXiv 2024

  32. [36]

    Altakach, P

    M.M. Altakach, P. Lamba, F. Maltoni, K. Mawatari and K. Sakurai,Quantum information and CP measurement inH→τ +τ − at future lepton colliders,Phys. Rev. D107(2023) 093002 [2211.10513]

    Pith/arXiv arXiv 2023

  33. [37]

    Ma and T

    K. Ma and T. Li,Testing Bell inequality throughh→τ τat CEPC*,Chin. Phys. C48(2024) 103105 [2309.08103]

    Pith/arXiv arXiv 2024

  34. [38]

    Ehat¨ aht, M

    K. Ehat¨ aht, M. Fabbrichesi, L. Marzola and C. Veelken,Probing entanglement and testing Bell inequality violation withe +e− →τ +τ − at Belle II,Phys. Rev. D109(2024) 032005 [2311.17555]

    Pith/arXiv arXiv 2024

  35. [39]

    Fabbrichesi and L

    M. Fabbrichesi and L. Marzola,Quantum tomography withτleptons at the FCC-ee: Entanglement, Bell inequality violation,sinθ W , and anomalous couplings,Phys. Rev. D110 (2024) 076004 [2405.09201]

    Pith/arXiv arXiv 2024

  36. [40]

    Fabbrichesi, M

    M. Fabbrichesi, M. Low and L. Marzola,Trace distance between density matrices: A nifty tool in new-physics searches,Phys. Rev. D112(2025) 013003 [2501.03311]

    Pith/arXiv arXiv 2025

  37. [41]

    T. Han, M. Low and Y. Su,Entanglement and Bell nonlocality inτ +τ − at the BEPC,JHEP 10(2025) 217 [2501.04801]

    arXiv 2025

  38. [42]

    Zhang, B.-H

    Y. Zhang, B.-H. Zhou, Q.-B. Liu, T.A. Wu, S. Li, T. Han et al.,Entanglement and Bell nonlocality inτ +τ − at the LHC using machine learning for neutrino reconstruction,JHEP04 (2026) 190 [2504.01496]

    Pith/arXiv arXiv 2026

  39. [43]

    Jeans,Experimental aspects of the quantum tomography of tau lepton pairs at a Higgs factory collider,Eur

    D. Jeans,Experimental aspects of the quantum tomography of tau lepton pairs at a Higgs factory collider,Eur. Phys. J. C86(2026) 549 [2603.12609]

    Pith/arXiv arXiv 2026

  40. [44]

    L. Lee, J. Lawless and C. Riggall,Higgs Boson Spookiness: Probing Quantum Nonlocality with Spacetime-ResolvedH→τ +τ − Decays,2603.28868

    arXiv

  41. [45]

    Barr,Testing Bell inequalities in Higgs boson decays,Phys

    A.J. Barr,Testing Bell inequalities in Higgs boson decays,Phys. Lett. B825(2022) 136866 [2106.01377]

    Pith/arXiv arXiv 2022

  42. [46]

    Aguilar-Saavedra, A

    J.A. Aguilar-Saavedra, A. Bernal, J.A. Casas and J.M. Moreno,Testing entanglement and Bell inequalities in H→ZZ,Phys. Rev. D107(2023) 016012 [2209.13441]. – 45 –

    Pith/arXiv arXiv 2023

  43. [47]

    Aguilar-Saavedra,Laboratory-frame tests of quantum entanglement in H→WW,Phys

    J.A. Aguilar-Saavedra,Laboratory-frame tests of quantum entanglement in H→WW,Phys. Rev. D107(2023) 076016 [2209.14033]

    Pith/arXiv arXiv 2023

  44. [48]

    Ashby-Pickering, A.J

    R. Ashby-Pickering, A.J. Barr and A. Wierzchucka,Quantum state tomography, entanglement detection and Bell violation prospects in weak decays of massive particles,JHEP05(2023) 020 [2209.13990]

    arXiv 2023

  45. [49]

    Fabbrichesi, R

    M. Fabbrichesi, R. Floreanini, E. Gabrielli and L. Marzola,Bell inequalities and quantum entanglement in weak gauge boson production at the LHC and future colliders,Eur. Phys. J. C 83(2023) 823 [2302.00683]

    Pith/arXiv arXiv 2023

  46. [50]

    Fabbrichesi, R

    M. Fabbrichesi, R. Floreanini, E. Gabrielli and L. Marzola,Stringent bounds on HWW and HZZ anomalous couplings with quantum tomography at the LHC,JHEP09(2023) 195 [2304.02403]

    Pith/arXiv arXiv 2023

  47. [51]

    Morales,Exploring Bell inequalities and quantum entanglement in vector boson scattering,Eur

    R.A. Morales,Exploring Bell inequalities and quantum entanglement in vector boson scattering,Eur. Phys. J. Plus138(2023) 1157 [2306.17247]

    Pith/arXiv arXiv 2023

  48. [52]

    Aoude, E

    R. Aoude, E. Madge, F. Maltoni and L. Mantani,Probing new physics through entanglement in diboson production,JHEP12(2023) 017 [2307.09675]

    Pith/arXiv arXiv 2023

  49. [53]

    Fabbri, J

    F. Fabbri, J. Howarth and T. Maurin,Isolating semi-leptonicH→W W ∗decays for Bell inequality tests,Eur. Phys. J. C84(2024) 20 [2307.13783]

    Pith/arXiv arXiv 2024

  50. [54]

    Bernal, P

    A. Bernal, P. Caban and J. Rembieli´ nski,Entanglement and Bell inequalities violation in H→ZZwith anomalous coupling,Eur. Phys. J. C83(2023) 1050 [2307.13496]

    Pith/arXiv arXiv 2023

  51. [55]

    Bi, Q.-H

    Q. Bi, Q.-H. Cao, K. Cheng and H. Zhang,New observables for testing Bell inequalities in W boson pair production,Phys. Rev. D109(2024) 036022 [2307.14895]

    Pith/arXiv arXiv 2024

  52. [56]

    Bernal, P

    A. Bernal, P. Caban and J. Rembieli´ nski,Entanglement and Bell inequality violation in vector diboson systems produced in decays of spin-0 particles,2405.16525

    Pith/arXiv arXiv

  53. [57]

    A. Ruzi, Y. Wu, R. Ding, S. Qian, A.M. Levin and Q. Li,Testing Bell inequalities and probing quantum entanglement at a muon collider,JHEP10(2024) 211 [2408.05429]

    Pith/arXiv arXiv 2024

  54. [58]

    Grossi, G

    M. Grossi, G. Pelliccioli and A. Vicini,From angular coefficients to quantum observables: a phenomenological appraisal in di-boson systems,JHEP12(2024) 120 [2409.16731]

    Pith/arXiv arXiv 2024

  55. [59]

    Y. Wu, R. Jiang, A. Ruzi, Y. Ban, X. Yan and Q. Li,Testing Bell inequalities and probing quantum entanglement at CEPC,Phys. Rev. D111(2025) 036008 [2410.17025]

    Pith/arXiv arXiv 2025

  56. [60]

    Sullivan,Constraining New Physics withh→V VTomography,2410.10980

    M. Sullivan,Constraining New Physics withh→V VTomography,2410.10980

    Pith/arXiv arXiv

  57. [61]

    Aguilar-Saavedra,H→ZZas a double-slit experiment,2411.13464

    J.A. Aguilar-Saavedra,H→ZZas a double-slit experiment,2411.13464

    Pith/arXiv arXiv

  58. [62]

    R. Ding, A. Ruzi, S. Qian, A. Levin, Y. Wu and Q. Li,Quantum Entanglement between gauge boson pairs at a Muon Collider,2504.09832

    Pith/arXiv arXiv

  59. [63]

    Del Gratta, F

    M. Del Gratta, F. Fabbri, P. Lamba, F. Maltoni and D. Pagani,Quantum properties of H→ VV∗: precise predictions in the SM and sensitivity to new physics,JHEP09(2025) 013 [2504.03841]

    Pith/arXiv arXiv 2025

  60. [64]

    Gon¸ calves, A

    D. Gon¸ calves, A. Kaladharan, F. Krauss and A. Navarro,Quantum entanglement is quantum: ZZ production at the LHC,JHEP12(2025) 122 [2505.12125]. – 46 –

    arXiv 2025

  61. [65]

    Aguilar-Saavedra,Quantum tomography beyond the leading order,Eur

    J.A. Aguilar-Saavedra,Quantum tomography beyond the leading order,Eur. Phys. J. C85 (2025) 969 [2505.11870]

    Pith/arXiv arXiv 2025

  62. [66]

    Gon¸ calves, A

    D. Gon¸ calves, A. Kaladharan and A. Navarro,Higher-order corrections to quantum observables in h→WW ∗,JHEP11(2025) 158 [2506.19951]

    arXiv 2025

  63. [67]

    A. Ruzi, Y. Wu, R. Ding and Q. Li,Searching Quantum Entanglement inp p→Z Zprocess, 2506.16077

    Pith/arXiv arXiv

  64. [68]

    Aguilar-Saavedra,Momentum entanglement at colliders: theH→W W, ZZcase, 2512.02104

    J.A. Aguilar-Saavedra,Momentum entanglement at colliders: theH→W W, ZZcase, 2512.02104

    arXiv

  65. [69]

    S. De, A. Dey and T. Samui,Unfolding quantum entanglement fromh→ZZ ∗ →jjℓℓat a muon collider,2512.09121

    arXiv

  66. [70]

    Pelliccioli and E

    G. Pelliccioli and E. Re,SMEFT effects on spin correlations and entanglement at NLO QCD in di-boson production at hadron colliders,2601.09540

    arXiv

  67. [71]

    Gon¸ calves, A

    D. Gon¸ calves, A. Kaladharan and A. Navarro,Quantum Tomography and Entanglement in Semi-Leptonich→V V ∗ Decays at Higher Orders,2604.16218

    Pith/arXiv arXiv

  68. [72]

    A.J. Barr, M. Fabbrichesi, R. Floreanini, E. Gabrielli and L. Marzola,Quantum entanglement and Bell inequality violation at colliders,Prog. Part. Nucl. Phys.139(2024) 104134 [2402.07972]

    Pith/arXiv arXiv 2024

  69. [73]

    Afik et al.,Quantum Information meets High-Energy Physics: Input to the update of the European Strategy for Particle Physics,2504.00086

    Y. Afik et al.,Quantum Information meets High-Energy Physics: Input to the update of the European Strategy for Particle Physics,2504.00086

    arXiv

  70. [74]

    Aoude, A.J

    R. Aoude, A.J. Barr, F. Maltoni and L. Satrioni,Decoherence effects in entangled fermion pairs at colliders,Phys. Rev. D113(2026) 076007 [2504.07030]

    Pith/arXiv arXiv 2026

  71. [75]

    Gu, S.-J

    J. Gu, S.-J. Lin, D.Y. Shao, L.-T. Wang and S.-X. Yang,Decoherence in high energy collisions as renormalization group flow,2510.13951

    arXiv

  72. [76]

    Aoude, J.M

    R. Aoude, J.M. Camacho, V. Durupt, G. Garc ´ ıa-Mir, F. Maltoni, M. Moreno Ll´ acer et al., Experimental prospects for quantum decoherence measurements at colliders,2604.16268

    Pith/arXiv arXiv

  73. [77]

    Cheng, T

    K. Cheng, T. Han, H. Singh and Y. Su,Decoherence and More Coherence in the Radiative Decay of theZBoson,2607.12015

    Pith/arXiv arXiv

  74. [78]

    Horodecki, P

    R. Horodecki, P. Horodecki, M. Horodecki and K. Horodecki,Quantum entanglement,Rev. Mod. Phys.81(2009) 865 [quant-ph/0702225]

    Pith/arXiv arXiv 2009

  75. [79]

    G¨ uhne and G

    O. G¨ uhne and G. T´ oth,Entanglement detection,Phys. Rept.474(2009) 1 [0811.2803]

    Pith/arXiv arXiv 2009

  76. [80]

    Coffman, J

    V. Coffman, J. Kundu and W.K. Wootters,Distributed entanglement,Phys. Rev. A61(2000) 052306 [quant-ph/9907047]

    Pith/arXiv arXiv 2000

  77. [81]

    Miyake,Classification of multipartite entangled states by multidimensional determinants, Phys

    A. Miyake,Classification of multipartite entangled states by multidimensional determinants, Phys. Rev. A67(2003) 012108 [quant-ph/0206111]

    Pith/arXiv arXiv 2003

  78. [82]

    Sakurai and M

    K. Sakurai and M. Spannowsky,Three-Body Entanglement in Particle Decays,Phys. Rev. Lett.132(2024) 151602 [2310.01477]

    Pith/arXiv arXiv 2024

  79. [83]

    Horodecki, K

    P. Horodecki, K. Sakurai, A.S. Shaleena and M. Spannowsky,Three-body non-locality in particle decays,JHEP10(2025) 160 [2502.19470]. – 47 –

    arXiv 2025

  80. [84]

    Aguilar-Saavedra,Tripartite entanglement in H→ZZ,WW decays,Phys

    J.A. Aguilar-Saavedra,Tripartite entanglement in H→ZZ,WW decays,Phys. Rev. D109 (2024) 113004 [2403.13942]

    Pith/arXiv arXiv 2024

Showing first 80 references.