Research output: Contribution to journal › Article › peer-review
ς+ and ς ¯-Polarization in the J/ψ and ψ (3686) Decays. / BESIII Collaboration.
In: Physical Review Letters, Vol. 125, No. 5, 052004, 31.07.2020.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - ς+ and ς ¯-Polarization in the J/ψ and ψ (3686) Decays
AU - BESIII Collaboration
AU - Ablikim, M.
AU - Achasov, M. N.
AU - Adlarson, P.
AU - Ahmed, S.
AU - Albrecht, M.
AU - Amoroso, A.
AU - An, Q.
AU - Anita,
AU - Bai, Y.
AU - Bakina, O.
AU - Ferroli, R. Baldini
AU - Balossino, I.
AU - Ban, Y.
AU - Begzsuren, K.
AU - Bennett, J. V.
AU - Berger, N.
AU - Bertani, M.
AU - Bettoni, D.
AU - Bianchi, F.
AU - Biernat, J.
AU - Bloms, J.
AU - Bortone, A.
AU - Boyko, I.
AU - Briere, R. A.
AU - Cai, H.
AU - Cai, X.
AU - Calcaterra, A.
AU - Cao, G. F.
AU - Cao, N.
AU - Cetin, S. A.
AU - Chang, J. F.
AU - Chang, W. L.
AU - Chelkov, G.
AU - Chen, D. Y.
AU - Chen, G.
AU - Chen, H. S.
AU - Chen, M. L.
AU - Chen, S. J.
AU - Chen, X. R.
AU - Chen, Y. B.
AU - Cheng, W.
AU - Cibinetto, G.
AU - Cossio, F.
AU - Cui, X. F.
AU - Dai, H. L.
AU - Dai, J. P.
AU - Dai, X. C.
AU - Dbeyssi, A.
AU - Muchnoi, N. Yu
AU - Nikolaev, I. B.
N1 - Publisher Copyright: © 2020 authors. Published by the American Physical Society. Funded by SCOAP3. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2020/7/31
Y1 - 2020/7/31
N2 - From 1310.6×106 J/ψ and 448.1×106 ψ(3686) events collected with the BESIII experiment, we report the first observation of ς+ and ς¯-spin polarization in e+e-→J/ψ[ψ(3686)]→ς+ς¯-decays. The relative phases of the form factors Δφ have been measured to be (-15.5±0.7±0.5)° and (21.7±4.0±0.8)° with J/ψ and ψ(3686) data, respectively. The nonzero value of Δφ allows for a direct and simultaneous measurement of the decay asymmetry parameters of ς+→pπ0(α0=-0.998±0.037±0.009) and ς¯-→p¯π0(α¯0=0.990±0.037±0.011), the latter value being determined for the first time. The average decay asymmetry, (α0-α¯0)/2, is calculated to be-0.994±0.004±0.002. The CP asymmetry ACP,ς=(α0+α¯0)/(α0-α¯0)=-0.004±0.037±0.010 is extracted for the first time, and is found to be consistent with CP conservation.
AB - From 1310.6×106 J/ψ and 448.1×106 ψ(3686) events collected with the BESIII experiment, we report the first observation of ς+ and ς¯-spin polarization in e+e-→J/ψ[ψ(3686)]→ς+ς¯-decays. The relative phases of the form factors Δφ have been measured to be (-15.5±0.7±0.5)° and (21.7±4.0±0.8)° with J/ψ and ψ(3686) data, respectively. The nonzero value of Δφ allows for a direct and simultaneous measurement of the decay asymmetry parameters of ς+→pπ0(α0=-0.998±0.037±0.009) and ς¯-→p¯π0(α¯0=0.990±0.037±0.011), the latter value being determined for the first time. The average decay asymmetry, (α0-α¯0)/2, is calculated to be-0.994±0.004±0.002. The CP asymmetry ACP,ς=(α0+α¯0)/(α0-α¯0)=-0.004±0.037±0.010 is extracted for the first time, and is found to be consistent with CP conservation.
UR - http://www.scopus.com/inward/record.url?scp=85089491962&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.125.052004
DO - 10.1103/PhysRevLett.125.052004
M3 - Article
C2 - 32794879
AN - SCOPUS:85089491962
VL - 125
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 5
M1 - 052004
ER -
ID: 27905145