Search for the lepton favor violating decay J/ψ→eμ  

作　　者：BESII Collaboratio 

机构地区：[1]不详

出　　处：《Science China(Physics,Mechanics & Astronomy)》2023年第2期24-33,共10页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Key Research and Development Program of China(Grant Nos.2020YFA0406400,and 2020YFA0406300);Joint Large-Scale Scientific Facility Funds of the National Natural Science Foundation of China(NSFC)and Chinese Academy of Sciences(CAS)(Grant Nos.U1932101,U1732263,and U1832207);State Key Laboratory of Nuclear Physics and Technology,Peking University(Grant No.NPT2020KFY04);National Natural Science Foundation of China(Grant Nos.11625523,11635010,11675275,11735014,11822506,11835012,11935015,11935016,11935018,11961141012,11975021,12022510,12035009,12035013,12061131003,and 12175321);CAS Center for Excellence in Particle Physics(CCEPP);CAS Large-Scale Scientific Facility Program;CAS Key Research Program of Frontier Sciences(Grant No.QYZDJSSW-SLH040);100 Talents Program of CAS,Fundamental Research Funds for the Central Universities,Institute of Nuclear and Particle Physics and Shanghai Key Laboratory for Particle Physics and Cosmology,European Research Council(Grant No.758462);European Union Horizon 2020 Research and Innovation Programme under Contract No.Marie SklodowskaCurie(Grant No.894790);German Research Foundation DFG(Grant No.443159800);Collaborative Research Center(Grant Nos.CRC 1044,FOR 2359,and GRK 2149);Istituto Nazionale di Fisica Nucleare,Italy,Ministry of Development of Turkey(Grant No.DPT2006K-120470);National Science and Technology fund,Olle Engkvist Foundation(Grant No.200-0605);Science and Technology Facilities Council(United Kingdom);The Knut and Alice Wallenberg Foundation(Sweden)(Grant No.2016.0157);The Royal Society,UK(Grant Nos.DH140054,and DH160214);The Swedish Research Council,U.S.Department of Energy(Grant Nos.DE-FG02-05ER41374,and DE-SC-0012069);the IHEP computing center for their strong support。

摘　　要：We present a search for the lepton flavor violating decay J/ψ→e±μ?using 8.998×109J/ψevents collected with the BESⅢdetector at the BEPCⅡe+e-storage ring.No excess of signal above background is observed;we therefore set an upper limit on the branching fraction of B(J/ψ→e±μ?)<4.5×10-9at the 90%confidence level.Improving the previous best result by a factor of more than 30,this measurement places the most stringent limit to date on lepton flavor violation in the heavy quarkonium sector.

关 键 词：BESⅢ DECAY LIMIT 

分 类 号：O571[理学—粒子物理与原子核物理]