Online The decay rate variation of r Be implanted into platinum and aluminum host materials has been measured via detecting the 478 keV γ-rays from the first excited state of r Li populated in the electron capture d...Online The decay rate variation of r Be implanted into platinum and aluminum host materials has been measured via detecting the 478 keV γ-rays from the first excited state of r Li populated in the electron capture decay of7r Be. The result （λpt - λA1）λ0 = （-0.17 ± 0.13）% is obtained. It is smaller than the theoretical estimate from the TB-LMTO calculation （0.38%）. This is quite different from our previous study which showed a 1arger decay rate variation （（0.8 ± 0.2）%） than the TB-LMTO calculation （0.30%） of 7 Be in palladium and gold. It is suggested that the effective quasi-free electron density near the implanted ions in different metal host materials may play an important role in r Be EC decay rate variation in addition to the electronic affinity and crystal structure of different host materials.展开更多
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 Coulomb barrier and electron screening cause difficulties in directly measuring nuclear reaction cross sections of charged particles at astrophysical energies. The Trojan-horse method （THM） has been introduced t...The Coulomb barrier and electron screening cause difficulties in directly measuring nuclear reaction cross sections of charged particles at astrophysical energies. The Trojan-horse method （THM） has been introduced to solve the difficulties as a powerful indirect tool. In order to understand experimentM spectra better, Geant4 is employed to simulate the method. Validity and reliability of simulation data are examined by comparing the experimental data with simulated results. The Geant4 simulation of THM future related experiments. improves data analysis and is beneficial to the design for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
The number of J/ψ events collected with the BES detector at the BEPC from June 12 to July 28, 2009 is determined to be （225.3 ± 2.8） × 10^ 6 using J/ψ→inclusive events, where the uncertainty is the syst...The number of J/ψ events collected with the BES detector at the BEPC from June 12 to July 28, 2009 is determined to be （225.3 ± 2.8） × 10^ 6 using J/ψ→inclusive events, where the uncertainty is the systematic error and the statistical one is negligible.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 10305020,
文摘Online The decay rate variation of r Be implanted into platinum and aluminum host materials has been measured via detecting the 478 keV γ-rays from the first excited state of r Li populated in the electron capture decay of7r Be. The result （λpt - λA1）λ0 = （-0.17 ± 0.13）% is obtained. It is smaller than the theoretical estimate from the TB-LMTO calculation （0.38%）. This is quite different from our previous study which showed a 1arger decay rate variation （（0.8 ± 0.2）%） than the TB-LMTO calculation （0.30%） of 7 Be in palladium and gold. It is suggested that the effective quasi-free electron density near the implanted ions in different metal host materials may play an important role in r Be EC decay rate variation in addition to the electronic affinity and crystal structure of different host materials.
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 National Natural Science Foundation of China(11075218,10575132)Beijing Natural Science Foundation(1122017)
文摘The Coulomb barrier and electron screening cause difficulties in directly measuring nuclear reaction cross sections of charged particles at astrophysical energies. The Trojan-horse method （THM） has been introduced to solve the difficulties as a powerful indirect tool. In order to understand experimentM spectra better, Geant4 is employed to simulate the method. Validity and reliability of simulation data are examined by comparing the experimental data with simulated results. The Geant4 simulation of THM future related experiments. improves data analysis and is beneficial to the design for
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 Ministry of Science and Technology of China (2009CB825200)National Natural Science Foundation of China (NSFC) (10625524, 10821063, 10825524, 10835001, 10935007, 11125525)+3 种基金Joint Funds of National Natural Science Foundation of China (11079008, 11179007)Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program (KJCX2-YW-N29, KJCX2-YW-N45)100 Talents Program of CAS, Istituto Nazionale di Fisica Nucleare, Italy, U. S. Department of Energy (DE-FG02-04ER41291, DE-FG02-91ER40682, DE-FG02-94ER40823)U.S. National Science Foundation, 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The number of J/ψ events collected with the BES detector at the BEPC from June 12 to July 28, 2009 is determined to be （225.3 ± 2.8） × 10^ 6 using J/ψ→inclusive events, where the uncertainty is the systematic error and the statistical one is negligible.
