Confirmation of theX(1835)and Observation of the ResonancesX(2120)andX(2370)inJ/ψ→γπ+π−η′

M Ablikim,Z L Hou,S Spataro,Y Nefedov,R A Briere,Y Ding,G F Xu,H M Hu,R G Ping,S X Du,Z J Xiao,X Wan,Q J Li,W L Yuan,S P Wen,Y Yuan,X Cai,L Y Dong,X Tang,F Li,X Y Song,J Fang,Y W Liu,Yong Liu,N Yu Muchnoi,Ling Zhao,C X Yu,R E Mitchell,Y Zhang,C D Fu,X H Mo,J K C Leung,D H Wei,S S Fang,Z Ning,X T Huang,X L Luo,S Jin,C Geng,Z A Liu,J F Chang,Fang Liu,M Shao,A A Zafar,B Zhong,J S Lange,J Zhong,Y H Guan,C Z Yuan,W B Yan,Y T Gu,Feng Liu,Y P Chu,Lei Li,T Hussain,L L Jiang,M H Ye,J B Jiao,Y S Zhu,M G Zhao,Z Y Deng,Cui Li,R Baldini,M Greco,Q An,Y Zeng,J C Chen,B Spruck,K Goetzen,M He,B S Zou,J Min,K L He,G X Sun,Q Liu,W X Gong,S Pacetti,J H Zou,H Y Sheng,A Zallo,S S Sun,M Qi,I Denysenko,L B Guo,J Zhuang,Y J Mao,K J Zhu,C L Luo,J F Hu,S L Olsen,M X Luo,Z Xue,B X Yu,M Pelizaeus,X S Qin,C J Tang,Cheng Li,J G Messchendorp,X Y Shen,X B Ji,M Y Dong,L H Wu,G Li,Y F Liang,H S Chen,J F Qiu,K H Rashid,Y K Heng,M Destefanis,C P Shen,X Y Zhang,D M Li,X S Jiang,H L Dai,Z P Mao,D P Jin,F Feldbauer,Z Jiao,H Y Zhang,W Kuehn,C C Zhang,A Q Guo,Y B Zhao,J P Dai,X Q Hao,M Bertani,Y H Yan,Z P Zhang,C S Ji,L Zhong,A Sarantsev,S J Zhao,Z J Sun,M R Shepherd,R Poling,S J Chen,Q Ouyang,C Motzko,J Z Bai,Z B Li,M H Gu,F A Harris,J G Lu,D Cronin-Hennessy,J C Li,G Rong,Y Ban,Z P Zheng,G F Cao,Z Y He,D Toth,M Maggiora,H Loehner,Q A Malik,Q Zhao,X K Zhou,M Kavatsyuk,T Hu,X Q Li,T Luo,Lu Jia ,M L Chen,Y J Sun,J L Ping,G Xu ,Y B Chen,X Liu,Zhongfu An ,Q Wang,H J Lü ,Nengyou Wu ,Xiaoyan Ma ,Bin Huang ,Y P Lu,J Z Zhang,X J Zhang,S B Liu,F C ,D H Sun,H B Li,Y T Liang,L Yan,B Zheng,Y H Zhang,Xu Zhao-Yu ,Tian Ma ,N Berger,X N Li,Y Zheng ,K Y Liu,H H Zhang,P Wang,L Zhou,Y F Wang,X L Ji,X R Li,J Y Zhang,G Varner ,Xuefeng Yin ,Z Wang,J W Zhang,Y Z Sun,K Zhu,Z T Sun,G R Liao ,G R Lu,X Zhao ,C S J Pun,D V Dedovich ,Y Gao,G Zhao,X L Li,Z Zhao ,Q W Lü ,K Liu,P L Wang,H S Zhao,J Becker,H S Xu ,G M Huang,Y Chen,Q Ji,Han Liu ,U Wiedner,G C Liu,D H Zhang,X T Liao,K Wang,F Jing ,B Q Wang,J X Zuo,W D Li,Y P Guo,N B Li,H X Yang,B X Zhang,S H Zhang,Z Y Zhang,J P Zheng,J Zhang,L L Wang,Z G Wang,M Yang,G Chen,K Peters,L Yu,S Sonoda,C Y Liu,X Zhu ,X L Wang,C F Qiao,Z A Zhu,S Qian,J Schulze,C Zhu,X Sun ,L Zhang,X R Lü ,H P Cheng,S H Zhu,Zhao Liu ,T C Zhao,J F Sun,X Y ,X R Zhou,H W Liu,H L ,Y B Liu,C L Liu,М Н Ачасов ,J Fu ,B Y Zhang,X X Cao,C X Liu,Yifan Yang ,W G Li,C Q Feng,P Zweber,Y Q Wang,G A Chelkov ,Zhi Wang ,L An,X D Ruan,V Bytev,A Zhemchugov,X H Liu,W Wu,T R Zhang,Y Yang,S V Grishin ,Y D Wang,S G Wang,J S Huang,I R Boyko ,Rui Fan ,H L Tian,M Ye,Z Y Wang,Mai-Ying Duan ,H B Liu,J W Zhao ,S Komamiya,L S Wang,C L ,H M Liu,B J Liu,M Wang,Q M ,J Z Zhao ,F H Liu,Y Xie ,H S Mao ,J P Liu,H Liu,J M Bian,Y Huang ,Z Q Liu,Tao Yang

doi:10.1103/physrevlett.106.072002

Abstract

With a sample of (225.2\pm2.8)*10^{6} J/psi events registered in the BESIII detector, J/psi->gamma pi^+ pi^- eta' is studied using two eta' decay modes: eta'->pi^+ pi^- eta and eta' -> gamma rho^0. The X(1835), which was previously observed by BESII, is confirmed with a statistical significance that is larger than 20\sigma. In addition, in the pi^+pi^-eta' invariant mass spectrum, the X(2120) and the X(2370), are observed with statistical significances larger than 7.2\sigma and 6.4\sigma, respectively. For the X(1835), the angular distribution of the radiative photon is consistent with expectations for a pseudoscalar.

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