ηπ+ π- resonant structure around 1.8 GeV/c(2) and η(1405) in J/ψ → ωηπ+ π

• Published in: Physical review letters 2011-10, Vol.107 (18), p.182001-182001
• Main Authors: Ablikim, M, Achasov, M N, Alberto, D, An, Q, An, Z H, Bai, J Z, Baldini, R, Ban, Y, Becker, J, Berger, N, Bertani, M, Bian, J M, Bondarenko, O, Boyko, I, Briere, R A, Bytev, V, Cai, X, Calcaterra, A C, Cao, G F, Cao, X X, Chang, J F, Chelkov, G, Chen, G, Chen, H S, Chen, J C, Chen, M L, Chen, S J, Chen, Y, Chen, Y B, Cheng, H P, Chu, Y P, Cronin-Hennessy, D, Dai, H L, Dai, J P, Dedovich, D, Deng, Z Y, Denysenko, I, Destefanis, M, Ding, Y, Dong, L Y, Dong, M Y, Du, S X, Fan, R R, Fang, J, Fang, S S, Feng, C Q, Fu, C D, Fu, J L, Gao, Y, Geng, C, Goetzen, K, Gong, W X, Greco, M, Grishin, S, Gu, M H, Gu, Y T, Guan, Y H, Guo, A Q, Guo, L B, Guo, Y P, Hao, X Q, Harris, F A, He, K L, He, M, He, Z Y, Heng, Y K, Hou, Z L, Hu, H M, Hu, J F, Hu, T, Huang, B, Huang, G M, Huang, J S, Huang, X T, Huang, Y P, Hussain, T, Ji, C S, Ji, Q, Ji, X B, Ji, X L, Jia, L K, Jiang, L L, Jiang, X S, Jiao, J B, Jiao, Z, Jin, D P, Jin, S, Jing, F F, Kalantar-Nayestanaki, N, Kavatsyuk, M, Komamiya, S, Kuehn, W, Lange, J S, Leung, J K C, Li, Cheng, Li, Cui, Li, D M, Li, F, Li, G, Li, H B
• Format: Article
• Language: English
• ISSN: 1079-7114

We present results of a study of the decay J/ψ → ωηπ+ π- using a sample of (225.2 ± 2.8) × 10(6) J/ψ events collected by the BESIII detector, and report the observation of a new process J/ψ → ωX(1870) with a statistical significance of 7.2σ, in which X(1870) decays to a(0)(±)(980)π±. Fitting to ηπ+ π- mass spectrum yields a mass M = 1877.3 ± 6.3(stat)(-7.4)(+3.4)(syst) MeV/c(2), a width Γ = 57 ± 12(stat)(-4)(+19)(syst) MeV/c(2), and a product branching fraction B(J/ψ → ωX) × B(X→a(0)(±)(980)π±) × B(a(0) (±)(980) → ηπ±) = [1.50 ± 0.26(stat)(-0.36)(+0.72) (syst)] × 10(-4). Signals for J/ψ → ωf(1)(1285) and J/ψ → ω η(1405) are also clearly observed and measured.