Observation of a p mass threshold enhancement in ψ′→π+π-J/ψ(J/ψ→γp) decay  

作　　者：麦迪娜 M. N. Achasov 安磊 安琪 安正华 白景芝 班勇 N. Berger 边渐鸣 I. Boyko R. A. Briere V. Bytev 蔡啸 曹国富 曹学香 常劲帆 G. Chelkov 陈刚 陈和生 陈江川 陈丽平 陈玛丽 陈鹏 陈申见 陈元柏 初元萍 D. Cronin-Hennessy 代洪亮 代建平 D. Dedovich 邓子艳 I. Denysenko M. Destefanis 丁勇 董燎原 董明义 杜书先 段麦英 方建 封常青 傅成栋 傅金林 高原宁 耿聪 K. Goetzen 龚文煊 M. Greco S. Grishin 顾运厅 郭爱强 郭立波 郭玉萍 韩少卿 F. A. Harris 何康林 何苗 何振亚 衡月昆 侯治龙 胡海明 胡继峰 胡涛 胡小为 黄彬 黄光明 黄金书 黄性涛 黄燕萍 姬长胜 纪全 季晓斌 季筱璐 贾卢魁 姜丽丽 江晓山 焦健斌 金大鹏 金山 S. Komamiya W. Kuehn S. Lange 梁干庄 李澄 李翠 李德民 李飞 李刚 李海波 李捷 李家才 李蕾 李陆 李秋菊 李卫东 李卫国 李晓玲 李小男 李学潜 李秀荣 李玉晓 李志兵 梁昊 梁泰然 Y.T. Liang 梁勇飞 廖广睿 廖小涛 刘北江 刘春秀 刘春燕 刘福虎 刘芳 刘峰 刘冠川 刘虎 刘宏邦 刘怀民 刘红薇 刘健 刘觉平 刘坤 刘魁勇 刘树彬 刘晓海 刘玉斌 刘艳芳 刘衍文 刘勇 刘振安 鲁公儒 吕军光 吕绮雯 吕晓睿 卢云鹏 罗成林 罗民兴Zhejiang University 罗涛 罗小兰 马长利 马凤才 马海龙 马秋梅 马想 马骁妍 M. Maggiora 冒亚军 毛泽普 闵建 莫晓虎 N. Yu. Muchnoi Y. Nefedov 宁飞鹏 S. L. Olsen 欧阳群 M. Pelizaeus K. Peters 

机构地区：[1]Institute of High Energy Physics,CAS [2]G.I. Budker Institute of Nuclear Physics SB RAS (BINP) [3]Guangxi University [4]University of Science and Technology of China [5]Peking University [6]Joint Institute for Nuclear Research [7]Carnegie Mellon University [8]the Moscow Institute of Physics and Technology [9]Nanjing University [10]University of Minnesota [11]the Bogolyubov Institute for Theoretical Physics [12]University of Turin and INFN [13]Liaoning University [14]Zhengzhou University [15]Shanxi University [16]Tsinghua University [17]GSI Helmholtzcentre for Heavy Ion Research GmbH,D-64291 Darmstadt,Germany [18]Nankai University [19]Nanjing Normal University [20]University of Hawaii [21]Graduate University of Chinese Academy of Sciences [22]Huazhong Normal University [23]Henan Normal University [24]Shandong University [25]The University of Tokyo [26]Universitaet Giessen [27]The University of Hong Kong [28]Sun Yat-Sen University [29]Sichuan University [30]Guangxi Normal University [31]The Chinese University of Hong Kong [32]Wuhan University [33]Seoul National University [34]Bochum Ruhr-University [35]China Center of Advanced Science and Technology [36]currently at Suzhou University [37]Hunan University

出　　处：《Chinese Physics C》2010年第4期421-426,共6页中国物理C（英文版）

基　　金：Supported by Ministry of Science and Technology of China (2009CB825200);National Natural Science Foundation of China(NSFC) (10625524,10821063,10825524,10835001,10935007);Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program,CAS (KJCX2-YW-N29,KJCX2-YW-N45);100 Talents Program of CAS;Istituto Nazionale di Fisica Nucleare,Italy,Russian Foundation for Basic Research (08-02-2221, 08-02-92200-NSFC-a);Siberian Branch of Russian Academy of Science,joint project No 32 with CAS,Chinese University of Hong Kong Focused Investment Grant (3110031);U. S. Department of Energy(DE-FG02-04ER41291,DE-FG02-91ER40682,DE-FG02-94ER40823);WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0);the A.P. Sloan Foundation

摘　　要：The decay channel ψ′→ π 〉＋π^-J/ψ（J/ψ 〉 γp^-p） is studied using a sample of 1.06 × 10^8 ψ′ events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the p^-p invariant mass spectrum. The enhancement can be fitted with an S-wave Breit-Wigner resonance function with a resulting peak mass of M = 1861-13^＋6 （stat）-26^＋7 （syst） MeV/c^2 and a narrow width that is Г 〈 38 MeV/c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with well established mesons.The decay channel ψ′→ π 〉＋π^-J/ψ（J/ψ 〉 γp^-p） is studied using a sample of 1.06 × 10^8 ψ′ events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the p^-p invariant mass spectrum. The enhancement can be fitted with an S-wave Breit-Wigner resonance function with a resulting peak mass of M = 1861-13^＋6 （stat）-26^＋7 （syst） MeV/c^2 and a narrow width that is Г 〈 38 MeV/c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with well established mesons.

关 键 词：p^-p threshold enhancement 

分 类 号：O571.3[理学—粒子物理与原子核物理]