TY - JOUR
T1 - First simultaneous measurement of Ξ0 and Ξ ¯ 0 asymmetry parameters in ψ (3686) decay
AU - Ablikim, M.
AU - Achasov, M. N.
AU - Adlarson, P.
AU - Aliberti, R.
AU - Kabana, S.
AU - The BESIII collaboration
N1 - 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 - 2023/7/1
Y1 - 2023/7/1
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 - https://www.scopus.com/pages/publications/85166419607
U2 - 10.1103/PhysRevD.108.L011101
DO - 10.1103/PhysRevD.108.L011101
M3 - Article
AN - SCOPUS:85166419607
SN - 2470-0010
VL - 108
JO - Physical Review D
JF - Physical Review D
IS - 1
M1 - L011101
ER -