We construct a quantum information-centered approach to describe the experimentally observed behavior of hyperon spin-pair correlations in high-energy collider experiments. The evolution of the spin density matrix of the hyperon pair is treated in the language of quantum channels, accounting both for the spin dynamics in $\mathbb{C}^2\otimes\mathbb{C}^2$ and for the pair's angular separation $ΔR$. We show that the experimental data are consistent with an evolution under a two-qubit depolarizing channel, from which a Lindblad master equation is derived. This provides an open quantum system picture of spin dynamics during the hadronization transition, which is not naturally captured by other quantum channels, and we discuss its microscopic origins. These results show that quantum information science can offer new insights into confinement dynamics beyond the classification of entanglement in the final particle states.
ΛΛˉ spin correlations in high-energy collisions from quantum channels: an open quantum system view of hadronization
We construct a quantum information-centered approach to describe the experimentally observed behavior of hyperon spin-pair correlations in high-energy collider experiments. The evolution of the spin density matrix of the hyperon pair is treated in the language of quantum channels, accounting both for the spin dynamics in C2⊗C2 and for the pair's angular separation ΔR. We show that the experimental data are consistent with an evolution under a two-qubit depolarizing channel, from which a Lindblad master equation is derived. This provides an open quantum system picture of spin dynamics during the hadronization transition, which is not naturally captured by other quantum channels, and we discuss its microscopic origins. These results show that quantum information science can offer new insights into confinement dynamics beyond the classification of entanglement in the final particle states.
Reply to Comment on "Controlling the Dynamical Evolution of Quantum Coherence and Quantum Correlations in e+e−→ΛΛˉ Processes at BESIII"
In the annihilation process e+e−→J/ψ→ΛΛˉ via J/ψ, the hyperon--antihyperon pair emerges from the same non-perturbative QCD hadronization process, where both spins develop in a common dense partonic environment. We describe the evolution of the ΛΛˉ spin degrees of freedom using correlated quantum channels that represent the effective influence of the common QCD hadronization environment on the two-spin system. The parameter μ characterizes the degree of environmental correlation resulting from the common hadronization process. Using the experimentally reconstructed spin density matrix, we evaluate quantum steering and investigate its robustness and dynamical evolution under correlated Markovian and non-Markovian quantum channels.
We comment on the recent work [Eur. Phys. J. C 86, 988 (2026)], which investigates quantum resources in polarized hyperon--antihyperon systems using correlated dephasing channels with memory. Although the use of experimentally reconstructed spin-density matrices to characterize quantum correlations in hyperon production may be a good motivation, we argue that the interpretation of the hyperon--antihyperon pair as an open quantum system undergoing correlated environmental decoherence is not physically established. In particular, no physical environment or system--environment interaction responsible for the assumed correlated dephasing channel is identified, and hadronization cannot simply be interpreted as such an environmental dephasing process. Consequently, the claimed non-Markovianity, information backflow, and memory-assisted protection of quantum resources should be regarded as properties of a phenomenological channel rather than established physical effects in hyperon--antihyperon production. We also identify several technical and conceptual issues concerning the dephasing dynamics, entanglement quantification, basis dependence of coherence, and the claimed hierarchy of quantum resources. These issues call for a substantial revision of the physical interpretation and quantitative conclusions of the work. We hope that the present Comment will help clarify the distinction between phenomenological quantum-channel modeling and physically established dynamical mechanisms in high-energy particle systems, and thereby provide useful guidance for future studies and help avoid similar conceptual and technical issues.
Qubit-Qutrit Quantum Tomography of hadronic Λφ and ΛK∗0 systems
Quantum-information observables have emerged in recent years as new tools in nuclear and particle physics, from entanglement in top-quark pairs to spin correlations in ΛΛˉ production. Extending these studies to unequal-spin hadronic final states poses a fundamental challenge: the 6×6 density matrix of a qubit-qutrit system contains 35 independent spin parameters, but the decays of ΛV pairs, with V=φ or K∗0, provide access to only 23 due to the hidden vector polarization from the strong decay. In this Letter, we formulate a qubit-qutrit quantum tomography (QQQT) technique for these spin-21⊗1 systems and establish exact criteria for entanglement certification from the \textit{incomplete} density matrix. Compared with the ΛΛˉ system, QQQT of Λφ and ΛK∗0 provides a new probe of nonperturbative QCD hadronization, enabling a direct comparison of the spin evolution of entangled quark pairs produced from the vacuum as they hadronize into a baryon or a vector meson.
Hyperon-antihyperon pairs produced from electron-positron annihilations provide a promising platform for exploring quantum-information properties in particle physics. In this work, we analyze quantum steering and quantum discord in hyperon-antihyperon systems produced from e + e − annihilations, based on the X -shaped spin density matrix reconstructed via quantum state tomography. We show that the behaviors of these correlations differ from those observed in elementary particle-antiparticle systems such as top quarks and τ leptons, owing to the polarization effects specific to hyperon decays. From the results, we examine the hierarchy of quantum correlations in hyperon-antihyperon systems, Bell nonlocality ⊂ steering ⊂ entanglement ⊂ discord . We also discuss the role of experimental loopholes and the impact of quantum decoherence in collider-based studies of quantum correlations.
Measurements of top quark properties in CMS: ttˉ spin density matrix, quantum entanglement and quantum magic
Polarization and spin correlation measurements of top quark-antiquark (ttˉ) pairs provide tests of the standard model, but also new ways to test quantum mechanics with unstable particles at highest energies ever produced in a laboratory. Recent ttˉ spin correlation measurements and the tests they enable, made with the CMS detector at the CERN LHC Run 2, are presented. The measurements summarized include the full spin density matrix measurement of top quark pairs using events with a single lepton and jets in the final state. Spin correlation measurements in specific phase space regions allow the observation of the entanglement phenomenon, and the measurement of quantum magic. From the measured spin correlation at the ttˉ production threshold and high ttˉ mass, entanglement is observed with a large fraction of the ttˉ decays being spacelike separated. The observation of entanglement in ttˉ events with two high transverse momentum leptons of opposite charge is also presented. Finally, the first TeV-scale experimental measurement of quantum magic, an important variable for the characterization of quantum states in quantum information science, is presented. These measurements provide one of the first connections between quantum information science and particle physics, and show the potential of collider experiments in the studies of the foundations of quantum mechanics.
Comment on "Controlling the dynamical evolution of quantum coherence and quantum correlations in e+e−→ΛΛˉ processes at BESIII''
We critically examine recent claims [Phys. Rev. D 113, 016024 (2026)] regarding quantum coherence, steering, and non-Markovian dynamics in the hyperon-antihyperon system produced in the process e+e−→ΛΛˉ. We argue that the theoretical framework employed in the analyzed work suffers from fundamental physical inconsistencies. In particular, the treatment of the ΛΛˉ pair as a bipartite system evolving under correlated quantum channels is not physically justified, since the produced hyperons are free, unstable particles that do not interact with a common environment after production. Consequently, the application of open quantum system techniques, including Markovian and non-Markovian quantum channels, lacks a clear physical basis. Moreover, we show that the computation and interpretation of quantum steering for this system is operationally and conceptually meaningless, as no well-defined measurement-induced state update or controllable local measurement scenario exists for unstable relativistic particles. These issues call into question the physical relevance of the reported quantum correlations, their hierarchy, and their dynamical behavior. Our analysis highlights the necessity of carefully distinguishing between formal mathematical quantifiers of quantumness and physically realizable quantum information protocols in high-energy particle systems.