Evidence of transverse polarization of the Ξ 0 hyperon in ψ ( 3686 ) → Ξ 0 Ξ ¯ 0

M. Ablikim; M. N. Achasov; P. Adlarson; X. Ai; R. Aliberti; A. Amoroso; Q. An; Yu Bai; Olga Bakina; Y. Ban; H. -R. Bao; V. Batozskaya; K. Begzsuren; N. Berger; M. Berlowski; M. B. Bertani; D. Bettoni; F. Bianchi; E. Bianco; A. Bortone; I. Boyko; Roy A. Briere; A. Brueggemann; Hanqing Cai; Minghui Cai; Xuanming Cai; A. Calcaterra; G. F. Cao; Nan Cao; Serkant Ali Cetin; X. Y. Chai; J. F. Chang; T. T. Chang; G. R. Che; Y. Che; Chao Chen; C. Chen; G. Chen; H. Y. Chen; H. S. Chen; M. L. Chen; Shaomin Chen; S. J. Chen; T. Chen; X. Y. Chen; X. R. Chen; X. T. Chen; Y. Q. Chen; Yihui Chen; Z. K. Chen; J. C. Cheng; L.N. Cheng; S. K. Choi; X. Chu; G. Cibinetto; F. Cossio; J. Cottee-Meldrum; H. L. Dai; J. P. Dai; X. C. Dai; A. Dbeyssi; R. E. de Boer; D. V. Dedovich; C. Q. Deng; Z. Y. Deng; A. Denig; I. Denisenko; M. Destefanis; F. De Mori; X. X. Ding; Y. X. Ding; Y. Ding; J. Dong; L. Y. Dong; M. Y. Dong; X. Dong; M. C. Du; S. X. Du; S. X. Du; Xiuli Du; Y. Y. Duan; Z. H. Duan; P. Egorov; Gaofeng Fan; J. J. Fan; Y. H. Fan; Jian Fang; J. Fang; S. S. Fang; Wenxing Fang; Y. Fang; L. Fava; F. Feldbauer; G. Felici; C. Q. Feng; J. H. Feng; J. H. Feng; Qichun Feng; Y. T. Feng; M. Fritsch

doi:10.1103/wrv9-t9vv

Evidence of transverse polarization of the Ξ 0 hyperon in ψ ( 3686 ) → Ξ 0 Ξ ¯ 0

Physical review. D/Physical review. D. 2026 Open access

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Authors: M. Ablikim, M. N. Achasov, P. Adlarson, X. Ai, R. Aliberti, A. Amoroso, Q. An, Yu Bai, Olga Bakina, Y. Ban, H. -R. Bao, V. Batozskaya

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K. Begzsuren, N. Berger, M. Berlowski, M. B. Bertani, D. Bettoni, F. Bianchi, E. Bianco, A. Bortone, I. Boyko, Roy A. Briere, A. Brueggemann, Hanqing Cai, Minghui Cai, Xuanming Cai, A. Calcaterra, G. F. Cao, Nan Cao, Serkant Ali Cetin, X. Y. Chai, J. F. Chang, T. T. Chang, G. R. Che, Y. Che, Chao Chen, C. Chen, G. Chen, H. Y. Chen, H. S. Chen, M. L. Chen, Shaomin Chen, S. J. Chen, T. Chen, X. Y. Chen, X. R. Chen, X. T. Chen, Y. Q. Chen, Yihui Chen, Z. K. Chen, J. C. Cheng, L.N. Cheng, S. K. Choi, X. Chu, G. Cibinetto, F. Cossio, J. Cottee-Meldrum, H. L. Dai, J. P. Dai, X. C. Dai, A. Dbeyssi, R. E. de Boer, D. V. Dedovich, C. Q. Deng, Z. Y. Deng, A. Denig, I. Denisenko, M. Destefanis, F. De Mori, X. X. Ding, Y. X. Ding, Y. Ding, J. Dong, L. Y. Dong, M. Y. Dong, X. Dong, M. C. Du, S. X. Du, S. X. Du, Xiuli Du, Y. Y. Duan, Z. H. Duan, P. Egorov, Gaofeng Fan, J. J. Fan, Y. H. Fan, Jian Fang, J. Fang, S. S. Fang, Wenxing Fang, Y. Fang, L. Fava, F. Feldbauer, G. Felici, C. Q. Feng, J. H. Feng, J. H. Feng, Qichun Feng, Y. T. Feng, M. Fritsch

DOI: 10.1103/wrv9-t9vv

Cited by: 1

References: 60

Abstract

Using ( 2.712 ± 0.014 ) × 10 9 ψ ( 3686 ) events collected with the BESIII detector at the BEPCII collider, we report an evidence of Ξ 0 transverse polarization with a significance of 4.4 σ , a precise measurement of the branching fraction and the ratios between the S -wave and D -wave contributions of ψ ( 3686 ) → Ξ 0 Ξ ¯ 0 . The weak decay parameters ( ϕ Ξ 0 / Ξ ¯ 0 , α Ξ 0 / Ξ ¯ 0 ) and the angular distribution ( α ψ ) are also measured with higher precision compared to the previous measurements. Furthermore, two the C P observables are also determined to be A C P Ξ 0 = − 0.014 ± 0.030 ± 0.010 and Δ ϕ C P Ξ 0 = 0.000 ± 0.028 ± 0.003 rad , which are still consistent with C P conservation at 1 σ level under the current statistics.

Fields of Study & Subjects

Quantum Chromodynamics and Particle Interactions Particle physics theoretical and experimental studies High-Energy Particle Collisions Research

Publication details

Journal / source: Physical review. D/Physical review. D.
Publisher: American Physical Society (APS)
Volume: 113
Issue: 9
Publication date: 26 March 2026
Language: EN

References 60