Bell nonlocality and entanglement in χ_cJ decays into baryon pair

We present a systematic analysis of Bell nonlocality and entanglement in χ_cJ$J=0,1,2$ decays into baryon pair$Bbar{B}$, with particular emphasis on their production via the process e^+e^- → ψ(2S) → γχ_cJ at BESIII. From the baryon-antibaryon spin density matrix, we construct measurable Bell observables and concurrence, revealing a striking hierarchy of quantum correlations: χ_c0 decays exhibit maximal violation and entanglement; χ_c1 decays violate Bell inequalities for θ₁ in (0, π) with angle-modulated strength; we find that the Bbar{B} pair in χ_c2 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 χ_cJ system produced via this radiative transition as a novel and promising platform for testing quantum entanglement and Bell nonlocality in high-energy collisions.