The number of φ' events accumulated by the BESIII experiment from March 3 through April 14, 2009, is determined by counting inclusive hadronic events. The result is 106.41×(1.00±0.81%)×10^6. The err...The number of φ' events accumulated by the BESIII experiment from March 3 through April 14, 2009, is determined by counting inclusive hadronic events. The result is 106.41×(1.00±0.81%)×10^6. The error is systematic dominant; the statistical error is negligible.展开更多
The numbers of ψ(3686) events accumulated by the BESⅢ detector for the data taken during 2009 and 2012 are determined to be(107.0±0.8)×10^6 and(341.1±2.1)×10^6, respectively, by counting in...The numbers of ψ(3686) events accumulated by the BESⅢ detector for the data taken during 2009 and 2012 are determined to be(107.0±0.8)×10^6 and(341.1±2.1)×10^6, respectively, by counting inclusive hadronic events,where the uncertainties are systematic and the statistical uncertainties are negligible. The number of events for the sample taken in 2009 is consistent with that of the previous measurement. The total number of ψ(3686) events for the two data taking periods is(448.1±2.9)×10^6.展开更多
From December 2011 to May 2014, about 5 fb^-1 of data were taken with the BESIII detector at center-of- mass energies between 3.810 GeV and 4.600 GeV to study the charmonium-like states and higher excited charmonium s...From December 2011 to May 2014, about 5 fb^-1 of data were taken with the BESIII detector at center-of- mass energies between 3.810 GeV and 4.600 GeV to study the charmonium-like states and higher excited charmonium states. The time-integrated luminosity of the collected data sample is measured to a precision of 1% by analyzing events produced by the large-angle Bhabha scattering process.展开更多
We report new measurements of the cross sections for the production of DD final states at theψ(3770)resonance.Our data sample consists of an integrated luminosity of 2.93 fb^(-1)of e~+e^-annihilation data produc...We report new measurements of the cross sections for the production of DD final states at theψ(3770)resonance.Our data sample consists of an integrated luminosity of 2.93 fb^(-1)of e~+e^-annihilation data produced by the BEPCⅡ collider and collected and analyzed with the BESⅢ detector.We exclusively reconstruct three D^0and six D~+hadronic decay modes and use the ratio of the yield of fully reconstructed DD events(“double tags”)to the yield of all reconstructed D or D mesons(“single tags”)to determine the number of D^0 D^0and D~+D^-events,benefiting from the cancellation of many systematic uncertainties.Combining these yields with an independent determination of the integrated luminosity of the data sample,we find the cross sections to beσ(e~+e^-→D^0D^0)=(3.615±0.010±0.038)nb andσ(e~+e^-→D~+D^-)=(2.830±0.011±0.026)nb,where the uncertainties are statistical and systematic,respectively.展开更多
Data sets were collected with the BESⅢ detector at the BEPCⅡ collider at the center-of-mass energy of √s=3.650 GeV during May 2009 and at √s=3.773 GeV from January 2010 to May 2011. By analyzing the large angle Bh...Data sets were collected with the BESⅢ detector at the BEPCⅡ collider at the center-of-mass energy of √s=3.650 GeV during May 2009 and at √s=3.773 GeV from January 2010 to May 2011. By analyzing the large angle Bhabha scattering events, the integrated luminosities of the two data sets are measured to be (44.49±0.02±0.44) pb-1 and (2916.94±0.18±29.17) pb-1, respectively, where the first error is statistical and the second error is systematic.展开更多
Using data samples collected at center-of-mass energies of √s=4.009, 4.230, 4.260, and 4.360 GeV with the BES0 detector operating at the BEPC/ collider, we perform a search for the process e+e-→γχc,j (J =0, 1, 2...Using data samples collected at center-of-mass energies of √s=4.009, 4.230, 4.260, and 4.360 GeV with the BES0 detector operating at the BEPC/ collider, we perform a search for the process e+e-→γχc,j (J =0, 1, 2) and find evidence for e+e-→γχc1 and e+e-→γχc2 with statistical significances of 3.0σ and 3.4σ, respectively. The Born cross sections σB(e+e-→γχc,j), as well as their upper limits at the 90% con dence level (C.L.) are determined at each center-of-mass energy.展开更多
基金Supported by Ministry of Science and Technology of China(2009CB825200)National Natural Science Foundation of China(NSFC)(10625524,10821063,10825524,10835001,10935007,11125525,10975143,10979058),Joint Funds of the National Natural Science Foundation of China(11079008,11179007)+5 种基金Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility ProgramCAS(KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CAS,Istituto Nazionale di Fisica Nucleare,Italy,Ministry of Development of Turkey(DPT2006K-120470)U.S.Department of Energy(DE-FG02-04ER41291,DE-FG02-91ER40682,DE-FG02-94ER40823)U.S.National Science Foundation,University of Groningen(RuG)the Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI),Darmstadt,WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘The number of φ' events accumulated by the BESIII experiment from March 3 through April 14, 2009, is determined by counting inclusive hadronic events. The result is 106.41×(1.00±0.81%)×10^6. The error is systematic dominant; the statistical error is negligible.
基金Supported by the Ministry of Science and Technology of China(2009CB825200)National Natural Science Foundation of China(NSFC)(11235011,11322544,11335008,11425524,11475207)+16 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Programthe Collaborative Innovation Center for Particlcs and Interactions(CICPI)Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(11179014)Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(11179007,U1232201,U1532257,U1532258)Joint Funds of the National Natural Science Foundation of China(11079008)CAS(KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CASNational 1000 Talents Program of ChinaGerman Research Foundation DFG(Collaborative Research Center CRC 1044)Istituto Nazionale di Fisica Nucleare,ItalyKoninklijke Nederlandse Akademie van Wetenschappen(KNAW)(530-4CDP03)Ministry of Development of Turkey(DPT2006K-120470)National Natural Science Foundation of China(11205082)The Swedish Research Council,U.S.Department of Energy(DE-FG02-05ER41374,DE-SC-0010118,DE-SC-0010504)U.S.National Science Foundation,University of Groningen(RuG)the Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI)Darmstadt,WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘The numbers of ψ(3686) events accumulated by the BESⅢ detector for the data taken during 2009 and 2012 are determined to be(107.0±0.8)×10^6 and(341.1±2.1)×10^6, respectively, by counting inclusive hadronic events,where the uncertainties are systematic and the statistical uncertainties are negligible. The number of events for the sample taken in 2009 is consistent with that of the previous measurement. The total number of ψ(3686) events for the two data taking periods is(448.1±2.9)×10^6.
基金Supported by National Key Basic Research Program of China(2015CB856700)National Natural Science Foundation of China(NSFC)(11125525,11235011,11322544,11335008,11425524)+5 种基金Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Program,Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(11179007,U1232201,U1332201)CAS(KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CAS,INPAC and Shanghai Key Laboratory for Particle Physics and Cosmology,German Research Foundation DFG(Collaborative Research Center CRC-1044),Istituto Nazionale di Fisica Nucleare,ItalyMinistry of Development of Turkey(DPT2006K-120470)Russian Foundation for Basic Research(14-07-91152)U.S.Department of Energy(DE-FG02-04ER41291,DE-FG02-05ER41374,DE-FG02-94ER40823,DESC0010118)U.S.National Science Foundation,University of Groningen(RUG)and the Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI),Darmstadt and WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘From December 2011 to May 2014, about 5 fb^-1 of data were taken with the BESIII detector at center-of- mass energies between 3.810 GeV and 4.600 GeV to study the charmonium-like states and higher excited charmonium states. The time-integrated luminosity of the collected data sample is measured to a precision of 1% by analyzing events produced by the large-angle Bhabha scattering process.
基金Supported by National Key Basic Research Program of China(2015CB856700)National Natural Science Foundation of China(NSFC)(11235011,11335008,11425524,11625523,11635010)+8 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Program,the CAS Center for Excellence in Particle Physics(CCEPP)Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(U1332201,U1532257,U1532258)CAS Key Research Program of Frontier Sciences(QYZDJ-SSW-SLH003,QYZDJ-SSW-SLH040)100 Talents Program of CAS,National 1000 Talents Program of China,INPAC and Shanghai 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 fund,The Swedish Research Council,U.S.Department of Energy(DEFG02-05ER41374,DE-SC-0010118,DE-SC-0010504,DE-SC-0012069)University of Groningen(Ru G)and the Helmholtzzentrum fuer Schwerionenforschung Gmb H(GSI)Darmstadt,WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘We report new measurements of the cross sections for the production of DD final states at theψ(3770)resonance.Our data sample consists of an integrated luminosity of 2.93 fb^(-1)of e~+e^-annihilation data produced by the BEPCⅡ collider and collected and analyzed with the BESⅢ detector.We exclusively reconstruct three D^0and six D~+hadronic decay modes and use the ratio of the yield of fully reconstructed DD events(“double tags”)to the yield of all reconstructed D or D mesons(“single tags”)to determine the number of D^0 D^0and D~+D^-events,benefiting from the cancellation of many systematic uncertainties.Combining these yields with an independent determination of the integrated luminosity of the data sample,we find the cross sections to beσ(e~+e^-→D^0D^0)=(3.615±0.010±0.038)nb andσ(e~+e^-→D~+D^-)=(2.830±0.011±0.026)nb,where the uncertainties are statistical and systematic,respectively.
基金Supported by the Ministry of Science and Technology of China(2009CB825204)National Natural Science Foundation of China(10625524,10821063,10825524,10835001,10935007,11125525,11235011)+7 种基金Joint Funds of the National Natural Science Foundation of China(11079008,11179007)Chinese Academy of Sciences Large-Scale Scientific Facility Program,CAS(KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CAS,German Research Foundation DFG(Collaborative Research Center CRC-1044)Istituto Nazionale di Fisica Nucleare,Italy,Ministry of Development of Turkey(DPT2006K-120470)U.S.Department of Energy(DE-FG02-04ER41291,DE-FG02-05ER41374,DE-FG02-94ER40823)U.S.National Science Foundation,University of Groningen(RuG)the Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI)Darmstadt,WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘Data sets were collected with the BESⅢ detector at the BEPCⅡ collider at the center-of-mass energy of √s=3.650 GeV during May 2009 and at √s=3.773 GeV from January 2010 to May 2011. By analyzing the large angle Bhabha scattering events, the integrated luminosities of the two data sets are measured to be (44.49±0.02±0.44) pb-1 and (2916.94±0.18±29.17) pb-1, respectively, where the first error is statistical and the second error is systematic.
基金Supported by National Key Basic Research Program of China(2015CB856700)Joint Funds of National Natural Science Foundation of China(11079008,11179007,U1232201,U1332201,U1232107)+7 种基金National Natural Science Foundation of China(NSFC)(10935007,11121092,11125525,11235011,11322544,11335008)Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Program,CAS(KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CAS,INPAC and Shanghai Key Laboratory for Particle Physics and CosmologyGerman Research Foundation DFG(Collaborative Research Center CRC-1044)Istituto Nazionale di Fisica Nucleare,Italy,Ministry of Development of Turkey(DPT2006K-120470)Russian Foundation for Basic Research(14-07-91152)U.S.Department of Energy(DE-FG02-04ER41291,DE-FG02-05ER41374,DE-FG02-94ER40823,DESC0010118)U.S.National Science Foundation,University of Groningen(RuG)and Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI),Darmstadt,WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘Using data samples collected at center-of-mass energies of √s=4.009, 4.230, 4.260, and 4.360 GeV with the BES0 detector operating at the BEPC/ collider, we perform a search for the process e+e-→γχc,j (J =0, 1, 2) and find evidence for e+e-→γχc1 and e+e-→γχc2 with statistical significances of 3.0σ and 3.4σ, respectively. The Born cross sections σB(e+e-→γχc,j), as well as their upper limits at the 90% con dence level (C.L.) are determined at each center-of-mass energy.