TY - JOUR

T1 - Observation of ψ(3686) → $$ {\Xi}^{-}{K}_S^0{\overline{\varOmega}}^{+} $$ + c.c.

AU - BESIII Collaboration

AU - Ablikim, M.

AU - Achasov, M. n.

AU - Nikolaev, I. b.

AU - Мучной, Николай Юрьевич

N1 - The BESIII Collaboration thanks the staff of BEPCII and the IHEP computing center for their strong support. This work is supported in part by National Key R&D Program of China under Contracts Nos. 2020YFA0406300, 2020YFA0406400, 2023YFA1606000; National Natural Science Foundation of China (NSFC) under Contracts Nos. 11635010, 11735014, 11935015, 11935016, 11935018, 12025502, 12035009, 12035013, 12061131003, 12165022, 12192260, 12192261, 12192262, 12192263, 12192264, 12192265, 12221005, 12225509, 12235017, 12342502, 12361141819; the China Postdoctoral Science Foundation under Grant Number 2024M753040; the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation under Grant Number GZC20241608; the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; the CAS Center for Excellence in Particle Physics (CCEPP); Joint Large-Scale Scientific Facility Funds of the NSFC and CAS under Contract No. U1832207; CAS under Contract No. YSBR-101; 100 Talents Program of CAS; the Beijing Natural Science Foundation under Grant Number IS23014; The Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology; Yunnan Fundamental Research Project under Contract No. 202301AT070162; Agencia Nacional de Investigación y Desarrollo de Chile (ANID), Chile under Contract No. ANID PIA/APOYO AFB230003; German Research Foundation DFG under Contract No. FOR5327; Istituto Nazionale di Fisica Nucleare, Italy; Knut and Alice Wallenberg Foundation under Contracts Nos. 2021.0174, 2021.0299; Ministry of Development of Turkey under Contract No. DPT2006K-120470; National Research Foundation of Korea under Contract No. NRF-2022R1A2C1092335; National Science and Technology fund of Mongolia; National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation of Thailand under Contract No. B50G670107; Polish National Science Centre under Contract No. 2019/35/O/ST2/02907; Swedish Research Council under Contract No. 2019.04595; The Swedish Foundation for International Cooperation in Research and Higher Education under Contract No. CH2018-7756; U.S. Department of Energy under Contract No. DE-FG02-05ER41374

PY - 2025/6/25

Y1 - 2025/6/25

N2 - Using a sample of (2.712 ± 0.014) × 109 ψ(3686) events collected with the BESIII detector at the electron positron collider BEPCII, the decay ψ(3686) → + c.c. is observed for the first time, which has a significance of 5.9 standard deviations. The branching fraction of this decay is measured to be (2.91 ± 0.47 ± 0.33) × 10−6, where the first and second uncertainties are statistical and systematic, respectively. The ratio between and is determined to be 1.05 ± 0.23 ± 0.14, which deviates from the isospin symmetry conservation predicted value of 0.5 by 2.1σ.

AB - Using a sample of (2.712 ± 0.014) × 109 ψ(3686) events collected with the BESIII detector at the electron positron collider BEPCII, the decay ψ(3686) → + c.c. is observed for the first time, which has a significance of 5.9 standard deviations. The branching fraction of this decay is measured to be (2.91 ± 0.47 ± 0.33) × 10−6, where the first and second uncertainties are statistical and systematic, respectively. The ratio between and is determined to be 1.05 ± 0.23 ± 0.14, which deviates from the isospin symmetry conservation predicted value of 0.5 by 2.1σ.

UR - https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=105012489195&origin=inward

U2 - 10.1007/JHEP06(2025)233

DO - 10.1007/JHEP06(2025)233

M3 - Article

VL - 2025

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

SN - 1029-8479

IS - 6

M1 - 233

ER -