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...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.展开更多
To investigate the nature of the Ψ（3770） resonance and to measure the cross section for e^＋e^-→DD, a cross-section scan data sample, distributed among 41 center-of-mass energy points from 3.73 to 3.89 GeV, was ta...To investigate the nature of the Ψ（3770） resonance and to measure the cross section for e^＋e^-→DD, a cross-section scan data sample, distributed among 41 center-of-mass energy points from 3.73 to 3.89 GeV, was taken with the BESIII detector operated at the BEPCII collider in the year 2010. By analyzing the large angle Bhabha scattering events, we measure the integrated luminosity of the data sample at each center-of-mass energy point. The total integrated luminosity of the data sample is 76.16±0.04±0.61 pb^-1, where the first uncertainty is statistical and the second systematic.展开更多
基金Supported by Ministry of Science and Technology of China (2009CB825200)National Natural Science Foundation of China(NSFC) (10625524,10821063,10825524,10835001,10935007)+6 种基金Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program,CAS (KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CASIstituto 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
文摘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.
基金Supported by National Key Basic Research Program of China(2015CB856700)National Natural Science Foundation of China(NSFC)(11235011,11335008,11425524,11625523,11635010)+13 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Programthe CAS Center for Excellence in Particle Physics(CCEPP)Joint Large-Scale Scientific Facility Funds of the NSFCCAS(U1332201,U1532257,U1532258)CAS Key Research Program of Frontier Sciences(QYZDJ-SSW-SLH003,QYZDJ-SSW-SLH040)100 Talents Program of CASNational 1000 Talents Program of China,INPACShanghai Key Laboratory for Particle Physics and Cosmology,German Research Foundation DFG under Contracts Nos.Collaborative Research Center CRC 1044,FOR 2359Istituto Nazionale di Fisica Nucleare,Italy,Koninklijke Nederlandse Akademie van Wetenschappen(KNAW)(530-4CDP03)Ministry of Development of Turkey(DPT2006K-120470)National Science and Technology fundThe Swedish Research Council,U.S.Department of Energy(DEFG02-05ER41374,DE-SC-0010118,DE-SC-0010504,DE-SC-0012069)University of Groningen(RuG)and the Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI)Darmstadt,WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘To investigate the nature of the Ψ（3770） resonance and to measure the cross section for e^＋e^-→DD, a cross-section scan data sample, distributed among 41 center-of-mass energy points from 3.73 to 3.89 GeV, was taken with the BESIII detector operated at the BEPCII collider in the year 2010. By analyzing the large angle Bhabha scattering events, we measure the integrated luminosity of the data sample at each center-of-mass energy point. The total integrated luminosity of the data sample is 76.16±0.04±0.61 pb^-1, where the first uncertainty is statistical and the second systematic.
