Two-photon widths of the $χ_{c0, 2}$ states and helicity analysis for $χ_{c2}\arγγ$}
Creators: name: BESIII Collaboration
name: Ablikim, M.
name: Achasov, M. N.
name: Ambrose, D. J.
name: An, F. F.
name: An, Q.
name: An, Z. H.
name: Bai, J. Z.
name: Ferroli, R. B.
name: Ban, Y.
name: Becker, J.
name: Berger, N.
name: Bertani, M. B.
name: Bian, J. M.
name: Boger, E.
name: Bondarenko, O.
name: Boyko, I.
name: Briere, R. A.
name: Bytev, V.
name: Cai, X.
name: Calcaterra, A. C.
name: Cao, G. F.
name: Chang, J. F.
name: Chelkov, G.
name: Chen, G.
name: Chen, H. S.
name: Chen, J. C.
name: Chen, M. L.
name: Chen, S. J.
name: Chen, Y.
name: Chen, Y. B.
name: Cheng, H. P.
name: Chu, Y. P.
name: Cronin-Hennessy, D.
name: Dai, H. L.
name: Dai, J. P.
name: Dedovich, D.
name: Deng, Z. Y.
name: Denig, A.
name: Denysenko, I.
name: Destefanis, M.
name: Ding, W. M.
name: Ding, Y.
name: Dong, L. Y.
name: Dong, M. Y.
name: Du, S. X.
name: Fang, J.
name: Fang, S. S.
name: Fava, L.
name: Feldbauer, F.
name: Feng, C. Q.
name: Fu, C. D.
name: Fu, J. L.
name: Gao, Y.
name: Geng, C.
name: Goetzen, K.
name: Gong, W. X.
name: Gradl, W.
name: Greco, M.
name: Gu, M. H.
name: Gu, Y. T.
name: Guan, Y. H.
name: Guo, A. Q.
name: Guo, L. B.
name: Guo, Y. P.
name: Han, Y. L.
name: Hao, X. Q.
name: Harris, F. A.
name: He, K. L.
name: He, M.
name: He, Z. Y.
name: Held, T.
name: Heng, Y. K.
name: Hou, Z. L.
name: Hu, H. M.
name: Hu, J. F.
name: Hu, T.
name: Huang, B.
name: Huang, G. M.
name: Huang, J. S.
name: Huang, X. T.
name: Huang, Y. P.
name: Hussain, T.
name: Ji, C. S.
name: Ji, Q.
name: Ji, X. B.
name: Ji, X. L.
name: Jia, L. K.
name: Jiang, L. L.
name: Jiang, X. S.
name: Jiao, J. B.
name: Jiao, Z.
name: Jin, D. P.
name: Jin, S.
name: Jing, F. F.
name: Kalantar-Nayestanaki, N.
name: Kavatsyuk, M.
name: Kuehn, W.
name: Lai, W.
name: Lange, J. S.
name: Leung, J. K. C.
name: Li, C. H.
name: Li, Cheng
name: Li, Cui
name: Li, D. M.
name: Li, F.
name: Li, G.
name: Li, H. B.
name: Li, J. C.
name: Li, K.
name: Li, Lei
name: Li, N. B.
name: Li, Q. J.
name: Li, S. L.
name: Li, W. D.
name: Li, W. G.
name: Li, X. L.
name: Li, X. N.
name: Li, X. Q.
name: Li, X. R.
name: Li, Z. B.
name: Liang, H.
name: Liang, Y. F.
name: Liang, Y. T.
name: Liao, G. R.
name: Liao, X. T.
name: Liu, B. J.
name: Liu, B. J.
name: Liu, C. L.
name: Liu, C. X.
name: Liu, C. Y.
name: Liu, F. H.
name: Liu, Fang
name: Liu, Feng
name: Liu, H.
name: Liu, H. B.
name: Liu, H. H.
name: Liu, H. M.
name: Liu, H. W.
name: Liu, J. P.
name: Liu, Kun
name: Liu, Kai
name: Liu, K. Y.
name: Liu, P. L.
name: Liu, S. B.
name: Liu, X.
name: Liu, X. H.
name: Liu, Y. B.
name: Liu, Y.
name: Liu, Z. A.
name: Liu, Zhiqiang
name: Liu, Zhiqing
name: Loehner, H.
name: Lu, G. R.
name: Lu, H. J.
name: Lu, J. G.
name: Lu, Q. W.
name: Lu, X. R.
name: Lu, Y. P.
name: Luo, C. L.
name: Luo, M. X.
name: Luo, T.
name: Luo, X. L.
name: Lv, M.
name: Ma, C. L.
name: Ma, F. C.
name: Ma, H. L.
name: Ma, Q. M.
name: Ma, S.
name: Ma, T.
name: Ma, X. Y.
name: Ma, Y.
name: Maas, F. E.
name: Maggiora, M.
name: Malik, Q. A.
name: Mao, H.
name: Mao, Y. J.
name: Mao, Z. P.
name: Messchendorp, J. G.
name: Min, J.
name: Min, T. J.
name: Mitchell, R. E.
name: Mo, X. H.
name: Morales, C. Morales
name: Motzko, C.
name: Muchnoi, N. Yu.
name: Nefedov, Y.
name: Nicholson, C.
name: Nikolaev, I. B.
name: Ning, Z.
name: Olsen, S. L.
name: Ouyang, Q.
name: Pacetti, S. P.
name: Park, J. W.
name: Pelizaeus, M.
name: Peters, K.
name: Ping, J. L.
name: Ping, R. G.
name: Poling, R.
name: Prencipe, E.
name: Pun, C. S. J.
name: Qi, M.
name: Qian, S.
name: Qiao, C. F.
name: Qin, X. S.
name: Qin, Y.
name: Qin, Z. H.
name: Qiu, J. F.
name: Rashid, K. H.
name: Rong, G.
name: Ruan, X. D.
name: Sarantsev, A.
name: Schulze, J.
name: Shao, M.
name: Shen, C. P.
name: Shen, X. Y.
name: Sheng, H. Y.
name: Shepherd, M. R.
name: Song, X. Y.
name: Spataro, S.
name: Spruck, B.
name: Sun, D. H.
name: Sun, G. X.
name: Sun, J. F.
name: Sun, S. S.
name: Sun, X. D.
name: Sun, Y. J.
name: Sun, Y. Z.
name: Sun, Z. J.
name: Sun, Z. T.
name: Tang, C. J.
name: Tang, X.
name: Thorndike, E. H.
name: Tian, H. L.
name: Toth, D.
name: Ulrich, M. U.
name: Varner, G. S.
name: Wang, B.
name: Wang, B. Q.
name: Wang, K.
name: Wang, L. L.
name: Wang, L. S.
name: Wang, M.
name: Wang, P.
name: Wang, P. L.
name: Wang, Q.
name: Wang, Q. J.
name: Wang, S. G.
name: Wang, X. F.
name: Wang, X. L.
name: Wang, Y. D.
name: Wang, Y. F.
name: Wang, Y. Q.
name: Wang, Z.
name: Wang, Z. G.
name: Wang, Z. Y.
name: Wei, D. H.
name: Weidenkaff, P.
name: Wen, Q. G.
name: Wen, S. P.
name: Werner, M. W.
name: Wiedner, U.
name: Wu, L. H.
name: Wu, N.
name: Wu, S. X.
name: Wu, W.
name: Wu, Z.
name: Xia, L. G.
name: Xiao, Z. J.
name: Xie, Y. G.
name: Xiu, Q. L.
name: Xu, G. F.
name: Xu, G. M.
name: Xu, H.
name: Xu, Q. J.
name: Xu, X. P.
name: Xu, Y.
name: Xu, Z. R.
name: Xue, F.
name: Xue, Z.
name: Yan, L.
name: Yan, W. B.
name: Yan, Y. H.
name: Yang, H. X.
name: Yang, T.
name: Yang, Y.
name: Yang, Y. X.
name: Ye, H.
name: Ye, M.
name: Ye, M. H.
name: Yu, B. X.
name: Yu, C. X.
name: Yu, J. S.
name: Yu, S. P.
name: Yuan, C. Z.
name: Yuan, W. L.
name: Yuan, Y.
name: Zafar, A. A.
name: Zallo, A. Z.
name: Zeng, Y.
name: Zhang, B. X.
name: Zhang, B. Y.
name: Zhang, C. C.
name: Zhang, D. H.
name: Zhang, H. H.
name: Zhang, H. Y.
name: Zhang, J.
name: Zhang, J. G.
name: Zhang, J. Q.
name: Zhang, J. W.
name: Zhang, J. Y.
name: Zhang, J. Z.
name: Zhang, L.
name: Zhang, S. H.
name: Zhang, T. R.
name: Zhang, X. J.
name: Zhang, X. Y.
name: Zhang, Y.
name: Zhang, Y. H.
name: Zhang, Y. S.
name: Zhang, Z. P.
name: Zhang, Z. Y.
name: Zhao, G.
name: Zhao, H. S.
name: Zhao, J. W.
name: Zhao, K. X.
name: Zhao, Lei
name: Zhao, Ling
name: Zhao, M. G.
name: Zhao, Q.
name: Zhao, S. J.
name: Zhao, T. C.
name: Zhao, X. H.
name: Zhao, Y. B.
name: Zhao, Z. G.
name: Zhemchugov, A.
name: Zheng, B.
name: Zheng, J. P.
name: Zheng, Y. H.
name: Zheng, Z. P.
name: Zhong, B.
name: Zhong, J.
name: Zhou, L.
name: Zhou, X. K.
name: Zhou, X. R.
name: Zhu, C.
name: Zhu, K.
name: Zhu, K. J.
name: Zhu, S. H.
name: Zhu, X. L.
name: Zhu, X. W.
name: Zhu, Y. M.
name: Zhu, Y. S.
name: Zhu, Z. A.
name: Zhuang, J.
name: Zou, B. S.
name: Zou, J. H.
name: Zuo, J. X.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Based on a data sample of 106 M $ψ^{\prime}$ events collected with the BESIII detector, the decays $ψ^{\prime}\arγχ_{c0, 2}$,$χ_{c0, 2}\arγγ$ are studied to determine the two-photon widths of the $χ_{c0, 2}$ states. The two-photon decay branching fractions are determined to be ${\cal B}(χ_{c0}\arγγ) = (2.24\pm 0.19\pm 0.12\pm 0.08)\times 10^{-4}$ and ${\cal B}(χ_{c2}\arγγ) = (3.21\pm 0.18\pm 0.17\pm 0.13)\times 10^{-4}$. From these, the two-photon widths are determined to be $Γ_{γγ}(χ_{c0}) = (2.33\pm0.20\pm0.13\pm0.17)$ keV, $Γ_{γγ}(χ_{c2}) = (0.63\pm0.04\pm0.04\pm0.04)$ keV, and $\cal R$ $=Γ_{γγ}(χ_{c2})/Γ_{γγ}(χ_{c0})=0.271\pm 0.029\pm 0.013\pm 0.027$, where the uncertainties are statistical, systematic, and those from the PDG ${\cal B}(ψ^{\prime}\arγχ_{c0,2})$ and $Γ(χ_{c0,2})$ errors, respectively. The ratio of the two-photon widths for helicity $λ=0$ and helicity $λ=2$ components in the decay $χ_{c2}\arγγ$ is measured for the first time to be $f_{0/2} =Γ^{λ=0}_{γγ}(χ_{c2})/Γ^{λ=2}_{γγ}(χ_{c2}) = 0.00\pm0.02\pm0.02$.
description: 10 pages, 4 figures