The decay ηc(2S) → π+π−η is searched for through the radiative transition ψ(3686) → γηc(2S) using 448 million ψ(3686) events accumulated at the BESIII detector. The first evidence of ηc(2S) → π+π−η is found with a statistical significance of 3.5σ. The product of the branching fractions of ψ(3686) → γηc(2S) and ηc(2S) → π+π−η is measured to be Br(ψ(3686) → γηc(2S)) × Br(ηc(2S) → π+π−η) =(2.97 pm 0.81 pm 0.26) × 10−6, where the first uncertainty is statistical and the second one is systematic. The branching fraction of the decay ηc(2S) → π+π−η is determined to be Br(ηc(2S) → π+π−η) = (42.4 pm 0..6 pm 0.8 pm 0.3) × 10−4, where the third uncertainty is transferred from the uncertainty of the branching fraction of ψ(3686) → γηc(2S).
Evidence for the ηc(2S) → π + π − η decay
Garzia I.;Scodeggio M.;
2023
Abstract
The decay ηc(2S) → π+π−η is searched for through the radiative transition ψ(3686) → γηc(2S) using 448 million ψ(3686) events accumulated at the BESIII detector. The first evidence of ηc(2S) → π+π−η is found with a statistical significance of 3.5σ. The product of the branching fractions of ψ(3686) → γηc(2S) and ηc(2S) → π+π−η is measured to be Br(ψ(3686) → γηc(2S)) × Br(ηc(2S) → π+π−η) =(2.97 pm 0.81 pm 0.26) × 10−6, where the first uncertainty is statistical and the second one is systematic. The branching fraction of the decay ηc(2S) → π+π−η is determined to be Br(ηc(2S) → π+π−η) = (42.4 pm 0..6 pm 0.8 pm 0.3) × 10−4, where the third uncertainty is transferred from the uncertainty of the branching fraction of ψ(3686) → γηc(2S).I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
