The hyperon-antihyperon pairs produced in electron-positron annihilation as a massive two-qubit quantum system can be used to study the quantum correlations at high energies. This paper is theoretically dedicated to how polarization of lepton beams manipulates the Bell nonlocality and entanglement of hyperon pair systems. The response of the Clauser–Horne–Shimony–Holt parameter, concurrence, and negativity to the polarization degree of the beam is numerically calculated by exploiting the joint spin density matrix of hyperon-antihyperon pairs. Different influences of longitudinal and transverse polarization of beams on entanglement are found and compared. The results provide alternative perspectives for the decay of charmonium to hyperon pairs.
A bstract Quantum entanglement and Bell nonlocality are two phenomena that occur only in quantum systems. In both cases, these are correlations between two subsystems that are classically absent. Traditionally, these phenomena have been measured in low-energy photon and electron experiments, but more recently they have also been measured in high-energy particle collider environments. In this work, we propose measuring the entanglement and Bell nonlocality in the τ + τ − state near and above its kinematic threshold at the Beijing Electron Positron Collider (BEPC). We find that in the existing dataset, entanglement is observable if systematic uncertainties are kept to 1%. In the upcoming run between 4.0 and 5.6 GeV, the entanglement is predicted to be measurable with a precision better than 4% and Bell nonlocality can be established at 5 σ as long as systematic uncertainty can be controlled at level of 0 . 5%–2 . 0%, depending on the center-of-mass energy.
Quantum entanglement and Bell nonlocality--cornerstones of quantum mechanics--have traditionally been investigated only in low-energy experimental settings. Only recently, these fundamental phenomena have come to be explored in the high-energy domain of particle physics, where collider experiments offer a powerful new platform for studying the phenomenology of quantum correlations. We present here recent results on the detection of entanglement and Bell nonlocality in processes such as tau-lepton,
WW, and
ZZ pair production, illustrating the potential of Future Lepton Colliders to probe the quantum properties of fundamental interactions.
Abstract Quantum entanglement and Bell nonlocality—cornerstones of quantum mechanics—have traditionally been investigated only in low-energy experimental settings. Only recently, these fundamental phenomena have come to be explored in the high-energy domain of particle physics, where collider experiments offer a powerful new platform for studying the phenomenology of quantum correlations. We present here recent results on the detection of entanglement and Bell nonlocality in processes such as tau–lepton, WW , and ZZ pair production, illustrating the potential of future lepton colliders to probe the quantum properties of fundamental interactions.
We present a systematic analysis of Bell nonlocality and entanglement in
χcJ(
J=0,1,2) decays into baryon pair(
BBˉ), with particular emphasis on their production via the process
e+e−→ψ(2S)→γχcJ at BESIII. From the baryon-antibaryon spin density matrix, we construct measurable Bell observables and concurrence, revealing a striking hierarchy of quantum correlations:
χc0 decays exhibit maximal violation and entanglement;
χc1 decays violate Bell inequalities for
θ1∈(0,π) with angle-modulated strength; we find that the
BBˉ pair in
χc2 decays is in a separable state, and no indication of Bell inequality violation is observed. We provide complete analytical results for
J=0,1 and quantitative, uncertainty-aware estimations for
J=2 based on experimental inputs from BESIII. These results establish the
χcJ system produced via this radiative transition as a novel and promising platform for testing quantum entanglement and Bell nonlocality in high-energy collisions.
Abstract The rapid developments of quantum information science (QIS) have opened up new avenues for exploring fundamental physics. Quantum nonlocality, a key aspect for distinguishing quantum information from classical one, has undergone extensive examinations in particles’ decays through the violation of Bell-type inequalities. Despite these advancements, a comprehensive framework based on quantum information theory for particle interaction is still lacking. Trying to close this gap, we introduce a generalized quantum measurement description for decay processes of spin-1/2 hyperons. We validate this approach by aligning it with established theoretical calculations and apply it to the joint decay of Λ Λ ¯ pairs. We employ quantum simulation to observe the violation of Clauser–Horne–Shimony–Holt inequalities in η c / χ c 0 → Λ Λ ¯ processes. Our generalized measurement description is adaptable and can be extended to a variety of high energy processes, including decays of vector mesons, J / ψ , ψ ( 2 S ) → Λ Λ ¯ , in the Beijing Spectrometer III (BESIII) experiment at the Beijing Electron Positron Collider (BEPC). The methodology developed in this study can be applied to quantum correlation and information processing in fundamental interactions.