TY - JOUR

T1 - Search for ηc (2S) →π+π-ηc and ηc (2S) →π+π- KS0 K±π∓ decays

AU - BESIII Collaboration

AU - Achasov, M. N.

AU - Nikolaev, I. B.

AU - Мучной, Николай Юрьевич

PY - 2024/4/1

Y1 - 2024/4/1

N2 - Based on (27.12±0.14)×108 ψ(2S) events collected by the BESIII detector, we search for the decay ηc(2S)→π+π-ηc via ψ(2S)→γηc(2S). No significant signal is observed, and the upper limit on the product branching fraction B(ψ(2S)→γηc(2S))×B(ηc(2S)→π+π-ηc) is determined to be 2.21×10-5 at the 90% confidence level. In addition, the ηc(2S)→π+π-KS0K±π∓ decay is studied via ψ(2S)→γηc(2S) and is observed with a statistical significance of 10σ for the first time. The branching fraction of ηc(2S)→π+π-KS0K±π∓ is determined to be (1.33±0.11±0.40±0.95)×10-2, where the first uncertainty is statistical, the second is systematic, and the third uncertainty is due to the quoted B(ψ(2S)→γηc(2S)).

AB - Based on (27.12±0.14)×108 ψ(2S) events collected by the BESIII detector, we search for the decay ηc(2S)→π+π-ηc via ψ(2S)→γηc(2S). No significant signal is observed, and the upper limit on the product branching fraction B(ψ(2S)→γηc(2S))×B(ηc(2S)→π+π-ηc) is determined to be 2.21×10-5 at the 90% confidence level. In addition, the ηc(2S)→π+π-KS0K±π∓ decay is studied via ψ(2S)→γηc(2S) and is observed with a statistical significance of 10σ for the first time. The branching fraction of ηc(2S)→π+π-KS0K±π∓ is determined to be (1.33±0.11±0.40±0.95)×10-2, where the first uncertainty is statistical, the second is systematic, and the third uncertainty is due to the quoted B(ψ(2S)→γηc(2S)).

UR - https://www.mendeley.com/catalogue/818d3765-672d-3b38-90eb-263a8c5223ad/

UR - https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85192753739&origin=inward

U2 - 10.1103/PhysRevD.109.072017

DO - 10.1103/PhysRevD.109.072017

M3 - Article

VL - 109

JO - Physical Review D

JF - Physical Review D

SN - 2470-0010

IS - 7

M1 - 072017

ER -