We study the application of BCFW recursion relations to the QED process 0→e^(-)e^(+)nγ.Based on 6-point amplitudes(both MHVA and NMHVA)computed from Feynman diagrams in the Berends-Giele gauge,we conduct a comprehen...We study the application of BCFW recursion relations to the QED process 0→e^(-)e^(+)nγ.Based on 6-point amplitudes(both MHVA and NMHVA)computed from Feynman diagrams in the Berends-Giele gauge,we conduct a comprehensive study on different shifts.Subsequently,we propose a new shift(LLYZ shift),which can lead to the full amplitudes of these processes and have several realistic computational advantages.We compare the number of terms and independent amplitudes of this novel shift with those of a few typical shifts.展开更多
From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ exper...From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ experiment.Using Bhabha and digamma events,we measure the integrated luminosity of the data sample to be(496.3±0.3±3.0) pb-1,where the first uncertainty is statistical and the second is systematic.This work provides a basis for future luminosity measurements at Belle Ⅱ.展开更多
基金Supported by the Natural Science Foundation of China (11475180, 11875260)Supported by the Italian Ministry of Research (MUR)(PRIN20172LNEEZ)
文摘We study the application of BCFW recursion relations to the QED process 0→e^(-)e^(+)nγ.Based on 6-point amplitudes(both MHVA and NMHVA)computed from Feynman diagrams in the Berends-Giele gauge,we conduct a comprehensive study on different shifts.Subsequently,we propose a new shift(LLYZ shift),which can lead to the full amplitudes of these processes and have several realistic computational advantages.We compare the number of terms and independent amplitudes of this novel shift with those of a few typical shifts.
基金supported by the following funding sources:Science Committee of the Republic of Armenia Grant No.18T-1C180Australian Research Council and research grant Nos.DP180102629,DP170102389,DP170102204,DP150103061,FT130100303,and FT130100018+37 种基金Austrian Federal Ministry of Education,Science and Research,and Austrian Science Fund No.P 31361-N36Natural Sciences and Engineering Research Council of Canada,Compute Canada and CANARIEChinese Academy of Sciences and research grant No.QYZDJ-SSW-SLH011National Natural Science Foundation of China and research grant Nos.11521505,11575017,11675166,11761141009,11705209,and 11975076LiaoNing Revitalization Talents Program under contract No.XLYC1807135Shanghai Municipal Science and Technology Committee under contract No.19ZR1403000Shanghai Pujiang Program under Grant No.18PJ1401000the CAS Center for Excellence in Particle Physics(CCEPP)the Ministry of Education,Youth and Sports of the Czech Republic under Contract No.LTT17020Charles University grants SVV260448 and GAUK 404316European Research Council,7th Framework PIEF-GA-2013-622527Horizon 2020 Marie Sklodowska-Curie grant agreement No.700525’NIOBE,’Horizon 2020 Marie Sklodowska-Curie RISE project JENNIFER grant agreement No.644294Horizon 2020 ERC-Advanced Grant No.267104NewAve No.638528(European grants)L’Institut National de Physique Nucléaire et de Physique des Particules(IN2P3)du CNRS(France),BMBF,DFG,HGF,MPG and AvH Foundation(Germany)Department of Atomic Energy and Department of Science and Technology(India)Israel Science Foundation grant No.2476/17United States-Israel Binational Science Foundation grant No.2016113Istituto Nazionale di Fisica Nucleare and the research grants BELLE2Japan Society for the Promotion of Science,Grant-in-Aid for Scientific Research grant Nos.16H03968,16H03993,16H06492,16K05323,17H01133,17H05405,18K03621,18H03710,18H05226,19H00682,26220706,and 26400255the National Institute of Informatics,and Science Information NETwork 5(SINET5)the Ministry of Education,Culture,Sports,Science,and Technology(MEXT)of JapanNational Research Foundation(NRF)of Korea Grant Nos.2016R1D1A1B01010135,2016R1D1A1B02012900,2018R1A2B3003643,2018R1A6A1A06024970,2018R1D1A1B07047294,2019K1A3A7A09033840,and 2019R1I1A3A01058933Radiation Science Research Institute,Foreign Large-size Research Facility Application Supporting project,the Global Science Experimental Data Hub Center of the Korea Institute of Science and Technology Information and KREONET/GLORIADUniversiti Malaya RU grant,Akademi Sains Malaysia and Ministry of Education MalaysiaFrontiers of Science Program contracts FOINS-296,CB-221329,CB-236394,CB-254409,and CB-180023,and the Thematic Networks program(Mexico)the Polish Ministry of Science and Higher Education and the National Science Centerthe Ministry of Science and Higher Education of the Russian Federation,Agreement14.W03.31.0026Slovenian Research Agency and research grant Nos.J1-9124 and P1-0135Agencia Estatal de Investigacion,Spain grant Nos.FPA2014-55613-P and FPA2017-84445-P,and CIDEGENT/2018/020 of Generalitat ValencianaMinistry of Science and Technology and research grant Nos.MOST106-2112-M-002-005-MY3 and MOST107-2119-M-002-035-MY3,and the Ministry of Education(Taiwan)Thailand Center of Excellence in PhysicsTUBITAK ULAKBIM(Turkey)Ministry of Education and Science of Ukrainethe US National Science Foundation and research grant Nos.PHY-1807007 and PHY-1913789the US Department of Energy and research grant Nos.DE-AC06-76RLO1830,DE-SC0007983,DE-SC0009824,DE-SC0009973,DE-SC0010073,DE-SC0010118,DE-SC0010504,DESC0011784,DE-SC0012704the National Foundation for Science and Technology Development(NAFOSTED)of Vietnam under grant No 103.99-2018.45
文摘From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ experiment.Using Bhabha and digamma events,we measure the integrated luminosity of the data sample to be(496.3±0.3±3.0) pb-1,where the first uncertainty is statistical and the second is systematic.This work provides a basis for future luminosity measurements at Belle Ⅱ.
