Using a data sample of 2.59×107 ψ(2S) decays obtained with the CLEO-c detector, we perform amplitude analyses of the complementary decay chains ψ(2S)→γχ c1; χ c1→ηπ +π - and ψ(2S)→γχ c1; χ c1→η ′π +π -. We find evidence for an exotic P-wave η ′π amplitude, which, if interpreted as a resonance, would have parameters consistent with the π 1(1600) state reported in other production mechanisms. We also make the first observation of the decay a 0(980) →η ′π and measure the ratio of branching fractions B(a 0(980)→η ′π)/B(a 0(980) →ηπ)=0.064±0.014±0.014. The ππ spectrum produced with a recoiling η is compared to that with η ′ recoil.
ASJC Scopus subject areas
- Nuclear and High Energy Physics