Work

Bell nonlocality and entanglement in χ c J decays into a baryon pair

Year: 2026

Type: article

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

Source: Physical review. D/Physical review. D.

DOI: 10.1103/8bx4-gfc4

Authors: Peng-Cheng Hong, Rong-Gang Ping, Wei-Min Song

Institutions: Jilin University, Institute of High Energy Physics, University of Chinese Academy of Sciences

Language: English

Topic: Quantum Chromodynamics and Particle Interactions

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funders: National Natural Science Foundation of China, People's Government of Jilin Province, Jilin Scientific and Technological Development Program

Awards: G4493315419, G4650760216