TY - JOUR
T1 - First simultaneous measurement of Ξ0 and Ξ ¯ 0 asymmetry parameters in ψ (3686) decay
AU - BESIII Collaboration
AU - Ablikim, M.
AU - Achasov, M. N.
AU - Kalantar-Nayestanaki, N.
AU - Kappert, R.
AU - Kavatsyuk, M.
AU - Messchendorp, J.
AU - Rodin, V.
N1 - Funding Information:
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 No. 2020YFA0406400, No. 2020YFA0406300; National Natural Science Foundation of China (NSFC) under Contracts No. 12075107, No. 12247101, No. 11635010, No. 11735014, No. 11835012, No. 11905236, No. 11935015, No. 11935016, No. 11935018, No. 11961141012, No. 12022510, No. 12025502, No. 12035009, No. 12035013, No. 12047501, No. 12061131003, No. 12192260, No. 12192261, No. 12192262, No. 12192263, No. 12192264, No. 12192265, No. 12225509; the 111 Project under Grant No. B20063; 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 Key Research Program of Frontier Sciences under Contracts No. QYZDJ-SSW-SLH003, No. QYZDJ-SSW-SLH040; 100 Talents Program of CAS; The Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology; ERC under Contract No. 758462; European Union’s Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement under Contract No. 894790; German Research Foundation DFG under Contracts No. 443159800, No. 455635585, Collaborative Research Center CRC 1044, FOR5327, GRK 2149; Istituto Nazionale di Fisica Nucleare, Italy; 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; National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation under Contract No. B16F640076; Polish National Science Centre under Contract No. 2019/35/O/ST2/02907; Suranaree University of Technology (SUT), Thailand Science Research and Innovation (TSRI), and National Science Research and Innovation Fund (NSRF) under Contract No. 160355; The Royal Society, UK under Contract No. DH160214; The Swedish Research Council; U.S. Department of Energy under Contract No. DE-FG02-05ER41374.
Publisher Copyright:
© 2023 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"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.
PY - 2023/7/7
Y1 - 2023/7/7
N2 - The Ξ0 asymmetry parameters are measured using entangled quantum Ξ0-Ξ¯0 pairs from a sample of (448.1±2.9)×106 ψ(3686) events collected with the BESIII detector at BEPCII. The relative phase between the transition amplitudes of the Ξ0Ξ¯0 helicity states is measured to be Δφ=-0.050±0.150±0.020 rad, which implies that there is no obvious polarization at the current level of statistics. The decay parameters of the Ξ0 hyperon (αΞ0,αΞ¯0,φΞ0,φΞ¯0) and the angular distribution parameter [αψ(3686)] and Δφ are measured simultaneously for the first time. In addition, the CP asymmetry observables are determined to be ACPΞ0=(αΞ0+αΞ¯0)/(αΞ0-αΞ¯0)=-0.007±0.082±0.025 and ΔφCPΞ0=(φΞ0+φΞ¯0)/2=-0.079±0.082±0.010 rad, which are consistent with CP conservation.
AB - The Ξ0 asymmetry parameters are measured using entangled quantum Ξ0-Ξ¯0 pairs from a sample of (448.1±2.9)×106 ψ(3686) events collected with the BESIII detector at BEPCII. The relative phase between the transition amplitudes of the Ξ0Ξ¯0 helicity states is measured to be Δφ=-0.050±0.150±0.020 rad, which implies that there is no obvious polarization at the current level of statistics. The decay parameters of the Ξ0 hyperon (αΞ0,αΞ¯0,φΞ0,φΞ¯0) and the angular distribution parameter [αψ(3686)] and Δφ are measured simultaneously for the first time. In addition, the CP asymmetry observables are determined to be ACPΞ0=(αΞ0+αΞ¯0)/(αΞ0-αΞ¯0)=-0.007±0.082±0.025 and ΔφCPΞ0=(φΞ0+φΞ¯0)/2=-0.079±0.082±0.010 rad, which are consistent with CP conservation.
UR - http://www.scopus.com/inward/record.url?scp=85166419607&partnerID=8YFLogxK
U2 - 10.1103/PhysRevD.108.L011101
DO - 10.1103/PhysRevD.108.L011101
M3 - Letter
SN - 2470-0010
VL - 108
JO - Physical Review D
JF - Physical Review D
IS - 1
M1 - L011101
ER -