We present a measurement of the integrated luminosity of e^(+)e^(-)collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm=3.773 GeV.The integrated luminosities of the ...We present a measurement of the integrated luminosity of e^(+)e^(-)collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm=3.773 GeV.The integrated luminosities of the datasets taken from December 2021 to June 2022,from November 2022 to June 2023,and from October 2023 to February 2024 were determined to be 4.995±0.019 fb^(-1),8.157±0.031 fb^(-1),and 4.191±0.016 fb^(-1),respectively,by analyzing large angle Bhabha scattering events.The uncertainties are dominated by systematic effects,and the statistical uncertainties are negligible.Our results provide essential input for future analyses and precision measurements.展开更多
The number ofψ(3686)events collected by the BESⅢdetector during the 2021 run period is determined to be(2259.3±11.1)×10~6 by counting inclusiveψ(3686)hadronic events.The uncertainty is systematic and the ...The number ofψ(3686)events collected by the BESⅢdetector during the 2021 run period is determined to be(2259.3±11.1)×10~6 by counting inclusiveψ(3686)hadronic events.The uncertainty is systematic and the statistical uncertainty is negligible.Meanwhile,the numbers ofψ(3686)events collected during the 2009 and 2012run periods are updated to be(107.7±0.6)×10~6 and(345.4±2.6)×10~6,respectively.Both numbers are consistent with the previous measurements within one standard deviation.The total number ofψ(3686)events in the three data samples is(2712.4±14.3)×10~6.展开更多
We report an improved measurement of the neutrino mixing angle θ13 from the Daya Bay Reactor Neutrino Experiment. We exclude a zero value for sin22θ13 with a significance of 7.7 standard deviations. Electron antineu...We report an improved measurement of the neutrino mixing angle θ13 from the Daya Bay Reactor Neutrino Experiment. We exclude a zero value for sin22θ13 with a significance of 7.7 standard deviations. Electron antineutrinos from six reactors of 2.9 GWm th were detected in six antineutrino detectors deployed in two near （flux-weighted baselines of 470 m and 576 m） and one far （1648 m） underground experimental halls. Using 139 days of data, 28909 （205308） electron antineutrino candidates were detected at the far hall （near halls）. The ratio of the observed to the expected number of antineutrinos assuming no oscillations at the far hall is 0.944± 0.007（stat.） ± 0.003（syst.）. An analysis of the relative rates in six detectors finds sin22θ13=0.089± 0.010（stat.）±0.005（syst.） in a three-neutrino framework.展开更多
To investigate the surface damage of a material by He ions,a dispersion-strengthened W-1wt%TiC alloy was irradiated by 5-keV He ions at 773 K,973 K,and 1173 K up to an ion dose of 1.8×10^(21)He m−2,respectively.N...To investigate the surface damage of a material by He ions,a dispersion-strengthened W-1wt%TiC alloy was irradiated by 5-keV He ions at 773 K,973 K,and 1173 K up to an ion dose of 1.8×10^(21)He m−2,respectively.No He bubble formation was observed under transmission electron microscopy at any temperature for He doses less than 1.5×10^(20)He m^(−2).When this dose was exceeded,He bubbles grew and void swelling increased with increasing irradiation doses.Naturally,the growth of He bubbles and the void swelling became more pronounced with increasing irradiation temperatures.Compared to the published data on commercially available pure W,the formation of He bubbles was suppressed by TiC particles in the W-TiC alloy,especially at low doses.展开更多
基金Supported in part by the National Key R&D Program of China(2020YFA0406400,2020YFA0406300,2023YFA1606000)the National Natural Science Foundation of China(123B2077,12035009,11635010,11735014,11875054,11935015,11935016,11935018,11961141012,12025502,12035013,12061131003,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017,12361141819)+8 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Program,the CAS Center for Excellence in Particle Physics(CCEPP),the Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(U2032104,U1832207)the Excellent Youth Foundation of Henan Scientific Commitee(242300421044)100 Talents Program of CASthe Institute of Nuclear and Particle Physics(INPAC)and Shanghai Key Laboratory for Particle Physics and Cosmology,German Research Foundation DFG(455635585,FOR5327,GRK 2149)Istituto Nazionale di Fisica Nucleare,Italy,Ministry of Development of Turkey(DPT2006K-120470)National Research Foundation of Korea(NRF-2022R1A2C1092335)National Science and Technology fund of Mongolia,National Science Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation of Thailand(B16F640076)Polish National Science Centre(2019/35/O/ST2/02907),the Swedish Research CouncilU.S.Department of Energy(DE-FG02-05ER41374)。
文摘We present a measurement of the integrated luminosity of e^(+)e^(-)collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm=3.773 GeV.The integrated luminosities of the datasets taken from December 2021 to June 2022,from November 2022 to June 2023,and from October 2023 to February 2024 were determined to be 4.995±0.019 fb^(-1),8.157±0.031 fb^(-1),and 4.191±0.016 fb^(-1),respectively,by analyzing large angle Bhabha scattering events.The uncertainties are dominated by systematic effects,and the statistical uncertainties are negligible.Our results provide essential input for future analyses and precision measurements.
基金supported in part by National Key R&D Program of China under Contracts Nos.2020YFA0406300,2020YFA0406400National Natural Science Foundation of China(NSFC)under Contracts Nos.12150004,11635010,11735014,11835012,11935015,11935016,11935018,11961141012,12025502,12035009,12035013,12061131003,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017+17 种基金the Program of Science and Technology Development Plan of Jilin Province of China under Contract Nos.20210508047RQ and 20230101021JCthe 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 NSFC and CAS under Contract No.U1832207CAS Key Research Program of Frontier Sciences under Contracts Nos.QYZDJ-SSW-SLH003,QYZDJ-SSW-SLH040100 Talents Program of CASThe Institute of Nuclear and Particle Physics(INPAC)Shanghai Key Laboratory for Particle Physics and CosmologyEuropean Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement under Contract No.894790German Research Foundation DFG under Contracts Nos.455635585,Collaborative Research Center CRC 1044,FOR5327,GRK 2149Istituto Nazionale di Fisica Nucleare,ItalyMinistry of Development of Turkey under Contract No.DPT2006K-120470National Research Foundation of Korea under Contract No.NRF-2022R1A2C1092335National Science and Technology fund of MongoliaNational Science Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation of Thailand under Contract No.B16F640076Polish National Science Centre under Contract No.2019/35/O/ST2/02907The Swedish Research CouncilU.S.Department of Energy under Contract No.DE-FG02-05ER41374。
文摘The number ofψ(3686)events collected by the BESⅢdetector during the 2021 run period is determined to be(2259.3±11.1)×10~6 by counting inclusiveψ(3686)hadronic events.The uncertainty is systematic and the statistical uncertainty is negligible.Meanwhile,the numbers ofψ(3686)events collected during the 2009 and 2012run periods are updated to be(107.7±0.6)×10~6 and(345.4±2.6)×10~6,respectively.Both numbers are consistent with the previous measurements within one standard deviation.The total number ofψ(3686)events in the three data samples is(2712.4±14.3)×10~6.
基金Supported by the Ministry of Science and Technology of Chinathe United States Department of Energy+15 种基金the Chinese Academy of Sciencesthe National Natural Science Foundation of Chinathe Guangdong provincial governmentthe Shenzhen municipal governmentthe China Guangdong Nuclear Power GroupShanghai Laboratory for Particle Physics and Cosmologythe Research Grants Council of the Hong Kong Special Administrative Region of ChinaUniversity Development Fund of The University of Hong Kongthe MOE program for Research of Excellence at NTU, NCTUNSC fund support from Taipeithe U.S. National Science Foundationthe Alfred P. Sloan Foundationthe Ministry of EducationYouth and Sports of the Czech Republicthe Czech Science Foundationthe Joint Institute of Nuclear Research in Dubna,Russia
文摘We report an improved measurement of the neutrino mixing angle θ13 from the Daya Bay Reactor Neutrino Experiment. We exclude a zero value for sin22θ13 with a significance of 7.7 standard deviations. Electron antineutrinos from six reactors of 2.9 GWm th were detected in six antineutrino detectors deployed in two near （flux-weighted baselines of 470 m and 576 m） and one far （1648 m） underground experimental halls. Using 139 days of data, 28909 （205308） electron antineutrino candidates were detected at the far hall （near halls）. The ratio of the observed to the expected number of antineutrinos assuming no oscillations at the far hall is 0.944± 0.007（stat.） ± 0.003（syst.）. An analysis of the relative rates in six detectors finds sin22θ13=0.089± 0.010（stat.）±0.005（syst.） in a three-neutrino framework.
基金the auspices of the NIFS Collaboration Research Program(Grant No.NIFS17KLPF055).
文摘To investigate the surface damage of a material by He ions,a dispersion-strengthened W-1wt%TiC alloy was irradiated by 5-keV He ions at 773 K,973 K,and 1173 K up to an ion dose of 1.8×10^(21)He m−2,respectively.No He bubble formation was observed under transmission electron microscopy at any temperature for He doses less than 1.5×10^(20)He m^(−2).When this dose was exceeded,He bubbles grew and void swelling increased with increasing irradiation doses.Naturally,the growth of He bubbles and the void swelling became more pronounced with increasing irradiation temperatures.Compared to the published data on commercially available pure W,the formation of He bubbles was suppressed by TiC particles in the W-TiC alloy,especially at low doses.
