2024/07/24 by BESIII Collaboration, Ablikim, M., Achasov, M. N. +645
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)
paper · doi:10.48550/arxiv.2407.17184
Using (2.712±0.014)×109 ψ(3686) events collected with the BESIII detector operating at the BEPCII, we find an evidence of the ηc(2S)→ K+ K- η′ decay with a statistical significance of 3.1σ. Its decay branching fraction is measured to be (12.24±4.60(stat.)±2.37(syst.)±4.68(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(3686)→γηc(2S) decay. The upper limit on the product branching fraction B[ψ(3686)→γηc(2S)] × B[ηc(2S)→ K+ K- η′] is set to be 1.14 × 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 (8.47±0.09(stat.)±0.47(syst.))× 10-4 and (1.53±0.04(stat.)±0.08(syst.))× 10-4, respectively. The precision is improved by twofold.