Ablikim, M.Achasov, M.N.Adlarson, P.Çetin, Serkant AliKolcu, Onur BuğraUman, Igor2025-04-182025-04-182025Ablikim, M., Achasov, M. N., Adlarson, P., Afedulidis, O., Ai, X. C., Aliberti, R., ... & Huang, K. X. (2025). Search for η c (2 S)→ K+ K-η′ decay. Physical Review D, 111(1), 012004.24700010http://dx.doi.org/10.1103/PhysRevD.111.012004https://hdl.handle.net/20.500.12713/6879Using (2.712±0.014)×109 ψ(2S) events collected with the BESIII detector operating at the BEPCII, we search for the ηc(2S)→K+K-η′ decay. Its decay branching fraction is measured to be (11.11±4.67(stat)±1.82(syst)±4.24(extr))×10-4, where the first uncertainty is statistical, the second is systematic, and the third uncertainty is from the branching fraction of the ψ(2S)→γηc(2S) decay. The statistical significance is 2.8σ. The upper limit on the product branching fraction B[ψ(2S)→γηc(2S)]×B[ηc(2S)→K+K-η′] is set to be 0.94×10-6 at 90% confidence level. In addition, the branching fractions of χc1→K+K-η′ and χc2→K+K-η′ are updated to be (8.48±0.10(stat)±0.47(syst))×10-4 and (1.53±0.04(stat)±0.08(syst))×10-4, respectively. The precision is improved by twofold. © 2025 authors. Published by the American Physical Society.eninfo:eu-repo/semantics/openAccessArticle11112-s2.0-8521724217110.1103/PhysRevD.111.012004Q1