Ablikim M, Achasov M N, Ahmed S, Ai X C, Albayrak O, Albrecht M, Ambrose D J, Amoroso A, An F F, An Q, Bai J Z, Bakina O, Baldini Ferroli R, Ban Y, Bennett D W, Bennett J V, Berger N, Bertani M, Bettoni D, Bian J M, Bianchi F, Boger E, Boyko I, Briere R A, Cai H, Cai X, Cakir O, Calcaterra A, Cao G F, Cetin S A, Chai J, Chang J F, Chelkov G, Chen G, Chen H S, Chen J C, Chen M L, Chen S, Chen S J, Chen X, Chen X R, Chen Y B, Chu X K, Cibinetto G, Dai H L, Dai J P, Dbeyssi A, Dedovich D, Deng Z Y, Denig A, Denysenko I, Destefanis M, De Mori F, Ding Y, Dong C, Dong J, Dong L Y, Dong M Y, Dou Z L, Du S X, Duan P F, Fan J Z, Fang J, Fang S S, Fang X, Fang Y, Farinelli R, Fava L, Feldbauer F, Felici G, Feng C Q, Fioravanti E, Fritsch M, Fu C D, Gao Q, Gao X L, Gao Y, Gao Z, Garzia I, Goetzen K, Gong L, Gong W X, Gradl W, Greco M, Gu M H, Gu Y T, Guan Y H, Guo A Q, Guo L B, Guo R P, Guo Y, Guo Y P, Haddadi Z, Hafner A, Han S, Hao X Q, Harris F A, He K L, Heinsius F H, Held T, Heng Y K, Holtmann T, Hou Z L, Hu C, Hu H M, Hu J F, Hu T, Hu Y, Huang G S, Huang J S, Huang X T, Huang X Z, Huang Z L, Hussain T, Ikegami Andersson W, Ji Q, Ji Q P, Ji X B, Ji X L, Jiang L W, Jiang X S, Jiang X Y, Jiao J B, Jiao Z, Jin D P, Jin S, Johansson T, Julin A, Kalantar-Nayestanaki N, Kang X L, Kang X S, Kavatsyuk M, Ke B C, Kiese P, Kliemt R, Kloss B, Kolcu O B, Kopf B, Kornicer M, Kupsc A, Kühn W, Lange J S, Lara M, Larin P, Lavezzi L, Leithoff H, Leng C, Li C, Li Cheng, Li D M, Li F, Li F Y, Li G, Li H B, Li H J, Li J C, Li Jin, Li K, Li K, Li Lei, Li P R, Li Q Y, Li T, Li W D, Li W G, Li X L, Li X N, Li X Q, Li Y B, Li Z B, Liang H, Liang Y F, Liang Y T, Liao G R, Lin D X, Liu B, Liu B J, Liu C X, Liu D, Liu F H, Liu Fang, Liu Feng, Liu H B, Liu H H, Liu H H, Liu H M, Liu J, Liu J B, Liu J P, Liu J Y, Liu K, Liu K Y, Liu L D, Liu P L, Liu Q, Liu S B, Liu X, Liu Y B, Liu Y Y, Liu Z A, Liu Zhiqing, Loehner H, Lou X C, Lu H J, Lu J G, Lu Y, Lu Y P, Luo C L, Luo M X, Luo T, Luo X L, Lyu X R, Ma F C, Ma H L, Ma L L, Ma M M, Ma Q M, Ma T, Ma X N, Ma X Y, Ma Y M, Maas F E, Maggiora M, Malik Q A, Mao Y J, Mao Z P, Marcello S, Messchendorp J G, Mezzadri G, Min J, Min T J, Mitchell R E, Mo X H, Mo Y J, Morales Morales C, Muchnoi N Yu, Muramatsu H, Musiol P, Nefedov Y, Nerling F, Nikolaev I B, Ning Z, Nisar S, Niu S L, Niu X Y, Olsen S L, Ouyang Q, Pacetti S, Pan Y, Patteri P, Pelizaeus M, Peng H P, Peters K, Pettersson J, Ping J L, Ping R G, Poling R, Prasad V, Qi H R, Qi M, Qian S, Qiao C F, Qin L Q, Qin N, Qin X S, Qin Z H, Qiu J F, Rashid K H, Redmer C F, Ripka M, Rong G, Rosner Ch, Ruan X D, Sarantsev A, Savrié M, Schnier C, Schoenning K, Shan W, Shao M, Shen C P, Shen P X, Shen X Y, Sheng H Y, Song W M, Song X Y, Sosio S, Spataro S, Sun G X, Sun J F, Sun S S, Sun X H, Sun Y J, Sun Y Z, Sun Z J, Sun Z T, Tang C J, Tang X, Tapan I, Thorndike E H, Tiemens M, Uman I, Varner G S, Wang B, Wang B L, Wang D, Wang D Y, Wang K, Wang L L, Wang L S, Wang M, Wang P, Wang P L, Wang W, Wang W P, Wang X F, Wang Y, Wang Y D, Wang Y F, Wang Y Q, Wang Z, Wang Z G, Wang Z H, Wang Z Y, Wang Z Y, Weber T, Wei D H, Weidenkaff P, Wen S P, Wiedner U, Wolke M, Wu L H, Wu L J, Wu Z, Xia L, Xia L G, Xia Y, Xiao D, Xiao H, Xiao Z J, Xie Y G, Xie Yuehong, Xiu Q L, Xu G F, Xu J J, Xu L, Xu Q J, Xu Q N, Xu X P, Yan L, Yan W B, Yan W C, Yan Y H, Yang H J, Yang H X, Yang L, Yang Y X, Ye M, Ye M H, Yin J H, You Z Y, Yu B X, Yu C X, Yu J S, Yuan C Z, Yuan Y, Yuncu A, Zafar A A, Zeng Y, Zeng Z, Zhang B X, Zhang B Y, Zhang C C, Zhang D H, Zhang H H, Zhang H Y, Zhang J, Zhang J J, Zhang J L, Zhang J Q, Zhang J W, Zhang J Y, Zhang J Z, Zhang K, Zhang L, Zhang S Q, Zhang X Y, Zhang Y, Zhang Y, Zhang Y H, Zhang Y N, Zhang Y T, Zhang Yu, Zhang Z H, Zhang Z P, Zhang Z Y, Zhao G, Zhao J W, Zhao J Y, Zhao J Z, Zhao Lei, Zhao Ling, Zhao M G, Zhao Q, Zhao Q W, Zhao S J, Zhao T C, Zhao Y B, Zhao Z G, Zhemchugov A, Zheng B, Zheng J P, Zheng W J, Zheng Y H, Zhong B, Zhou L, Zhou X, Zhou X K, Zhou X R, Zhou X Y, Zhu K, Zhu K J, Zhu S, Zhu S H, Zhu X L, Zhu Y C, Zhu Y S, Zhu Z A, Zhuang J, Zotti L, Zou B S, Zou J H
Institute of High Energy Physics, Beijing 100049, People's Republic of China.
G.I. Budker Institute of Nuclear Physics SB RAS (BINP), Novosibirsk 630090, Russia.
Phys Rev Lett. 2017 Mar 3;118(9):092002. doi: 10.1103/PhysRevLett.118.092002. Epub 2017 Mar 1.
The cross sections of e^{+}e^{-}→π^{+}π^{-}h_{c} at center-of-mass energies from 3.896 to 4.600 GeV are measured using data samples collected with the BESIII detector operating at the Beijing Electron Positron Collider. The cross sections are found to be of the same order of magnitude as those of e^{+}e^{-}→π^{+}π^{-}J/ψ and e^{+}e^{-}→π^{+}π^{-}ψ(2S), but the line shape is inconsistent with the Y states observed in the latter two modes. Two structures are observed in the e^{+}e^{-}→π^{+}π^{-}h_{c} cross sections around 4.22 and 4.39 GeV/c^{2}, which we call Y(4220) and Y(4390), respectively. A fit with a coherent sum of two Breit-Wigner functions results in a mass of (4218.4_{-4.5}^{+5.5}±0.9) MeV/c^{2} and a width of (66.0_{-8.3}^{+12.3}±0.4) MeV for the Y(4220), and a mass of (4391.5_{-6.8}^{+6.3}±1.0) MeV/c^{2} and a width of (139.5_{-20.6}^{+16.2}±0.6) MeV for the Y(4390), where the first uncertainties are statistical and the second ones systematic. The statistical significance of Y(4220) and Y(4390) is 10σ over one structure assumption.
利用在北京正负电子对撞机上运行的北京谱仪III（BESIII）探测器收集的数据样本，测量了质心能量从3.896到4.600 GeV时(e^{+}e^{-}\to\pi^{+}\pi^{-}h_{c})的截面。发现该截面与(e^{+}e^{-}\to\pi^{+}\pi^{-}J/\psi)和(e^{+}e^{-}\to\pi^{+}\pi^{-}\psi(2S))的截面处于同一量级，但线形与后两种模式中观测到的Y态不一致。在(e^{+}e^{-}\to\pi^{+}\pi^{-}h_{c})截面中，在约4.22和4.39 GeV/(c^{2})处观测到两个结构，我们分别称之为Y(4220)和Y(4390)。用两个布赖特-维格纳函数的相干和进行拟合，得到Y(4220)的质量为((4218.4_{-4.5}^{+5.5}\pm0.9)) MeV/(c^{2})，宽度为((66.0_{-8.3}^{+12.3}\pm0.4)) MeV；Y(4390)的质量为((4391.5_{-6.8}^{+6.3}\pm1.0)) MeV/(c^{2})，宽度为((139.5_{-20.6}^{+16.2}\pm0.6)) MeV，其中第一个不确定度为统计不确定度，第二个为系统不确定度。在单结构假设下，Y(4220)和Y(4390)的统计显著性为10σ。
