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Polarization analysis in $e^{+} e^{-} \to J / ψ \to$ baryon-antibaryon pairs

Zhe Zhang ^1,*, Tianbo Liu ^2,1,†, Rong-Gang Ping ^3,4,‡, Jiao Jiao Song^5,§, and Weihua Yang ^6,∥

¹Southern Center for Nuclear-Science Theory (SCNT), Institute of Modern Physics, Chinese Academy of Sciences, Huizhou 516000, People’s Republic of China
²Key Laboratory of Particle Physics and Particle Irradiation (MOE), Institute of Frontier and Interdisciplinary Science, Shandong University, Qingdao, Shandong 266237, People’s Republic of China
³Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
⁴University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
⁵School of Physics, He’nan Normal University, Xinxiang, Henan 453007, People’s Republic of China
⁶College of Nuclear Equipment and Nuclear Engineering, Yantai University, Yantai, Shandong 264005, People’s Republic of China

^*Contact author: zhangzhe@impcas.ac.cn
^†Contact author: liutb@sdu.edu.cn
^‡Contact author: pingrg@mail.ihep.ac.cn
^§Contact author: songjiaojiao@ihep.ac.cn
^∥Contact author: yangwh@ytu.edu.cn

Phys. Rev. D 112, 096012 – Published 10 November, 2025

DOI: https://doi.org/10.1103/mzkm-qw8w

Abstract

We present a comprehensive polarization analysis for the process $e^{+} e^{-} \to J / ψ \to$ baryon-antibaryon pairs $B_{1} {\bar{B}}_{2}$ . All possible helicity amplitudes for $e^{+} e^{-} \to J / ψ$ and $J / ψ \to B_{1} {\bar{B}}_{2}$ are provided, along with their transformation properties under parity and $C P$ operations. Taking full account of beam polarization, we analyze the polarization of the $J / ψ$ produced in $e^{+} e^{-}$ annihilation and show that all eight independent polarization components can be nonzero. By introducing a polarization transfer matrix, we propose a novel method to compute the polarization transfer in the decay $J / ψ \to B_{1} {\bar{B}}_{2}$ . Considering both hadronic and radiative baryon decay models, we derive the joint angular distribution of the final-state particles. Focusing on the process $J / ψ \to Λ {\bar{Σ}}^{0}$ , we provide statistical uncertainty estimates for probing $C P$ violation in associated production of different baryons. This work establishes a complete framework for studying the parity and $C P$ violations present in baryon productions and decays within the helicity formalism.

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Phys. Rev. D 112, 096012– Published 10 November, 2025

Vol. 112, Iss. 9 — 1 November 2025

Received 9 August 2025
Accepted 17 October 2025

DOI: https://doi.org/10.1103/mzkm-qw8w

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

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Polarization analysis in $e^{+} e^{-} \to J / ψ \to$ baryon-antibaryon pairs

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Polarization analysis in e+e−→J/ψ→ baryon-antibaryon pairs

Abstract

Physics Subject Headings (PhySH)

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References (80)

Polarization analysis in $e^{+} e^{-} \to J / ψ \to$ baryon-antibaryon pairs