Partial wave analysis of J/ ψ→ γ( ηπ+π−)

• Published in: Physics letters. B Vol. 446; no. 3; pp. 356 - 362
• Main Authors: Bai, J.Z., Ban, Y., Chen, J.C., Chen, Y., Chen, Y.Q., Cui, X.Z., Ding, H.L., Dong, L.Y., Gao, C.S., Gao, M.L., Gao, S.Q., Gu, W.X., Gu, Y.F., Guo, Y.N., Han, S.W., Han, Y., He, K.L., Hu, H.M., Hu, J.L., Hu, Q.H., Hu, X.Q., Huang, Y.Z., Jiang, C.H., Lang, P.F., Li, C.G., Li, D., Li, P.Q., Li, R.B., Li, W.G., Li, X.N., Liu, R.G., Lu, J.G., Luo, X.L., Ma, E.C., Ma, J.M., Mao, H.S., Mao, Z.P., Qi, N.D., Qi, X.R., Que, Y.K., Rong, G., Shao, Y.Y., Shen, B.W., Shen, D.L., Shen, H., Shen, X.Y., Sheng, H.Y., Song, X.F., Sun, H.S., Sun, Y., Sun, Y.Z., Wang, F., Wang, Meng, Wang, S.M., Wang, Y.Y., Xi, D.M., Xia, X.M., Xie, P.P., Xie, Y., Xue, S.T., Yan, J., Yan, W.G., Yang, C.M., Yang, C.Y., Yang, X.F., Ye, S.W., Ye, Y.X., Yu, C.S., Yu, G.W., Yu, Z.Q., Yuan, C.Z., Yuan, Y., Zhang, B.Y., Zhang, C.C., Zhang, D.H., Zhang, Dehong, Zhang, H.L., Zhang, J., Zhang, Q.J., Zhang, S.Q., Zhang, Y.Y., Zhao, D.X., Zhao, H.W., Zhao, J.W., Zhao, W.R., Zhao, Z.G., Zheng, J.P., Zheng, L.S., Zheng, Z.P., Zhou, B.Q., Zhou, G.P., Zhou, H.S., Zhou, L., Zhu, K.J., Zhu, Q.M., Zhu, Y.C., Zhuang, B.A., Bugg, D.V., Sarantsev, A.V., Zou, B.S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1999
• Subjects: 12.39.Mk; 14.40.Cs; 13.25.Jx; 13.40.Hq
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/S0370-2693(98)01445-2

A partial wave analysis of BES J/ ψ→ γ( ηπ + π −) data has been performed in the mass region 1.1 to 2.0 GeV. A peak is observed due to η(1440) in the ηπ + π − invariant mass distribution; J P =0 − is preferred over 1 +. Its mass is M=1385±7 MeV and it decays into both ησ and a 0(980) π, with BR[ a 0(980) π, a 0→ ηπ/ ησ]=0.70±0.12( stat)±0.20( syst). Destructive interference between the two decay modes is observed. In addition, in the higher ηπ + π − mass region, there is a definite 2 −+ signal, with M=1840±15 MeV and Γ=170±40 MeV and an additional 0 −+ signal at 1760±35 MeV. We also find a possible contribution from a 1 ++ signal decaying dominantly through a 0(980) π; its mass and width are fitted to be M=1505±20 MeV and Γ=130 −20 +50 MeV.