中国科学院：高能物理研究所的粒子物理研究 Particle Physics Research in Institute of High Energy Physics

Particle Physics Research in iNstitute of High Energy Physics 陈和生( Hesheng chen) Institute of High Energy Physics Chinese academy of sciences

1 Institute of High Energy Physics Chinese Academy of Sciences Particle Physics Research in Institute of High Energy Physics 陈和生 (Hesheng Chen)

Institute of High Energy Physics Comprehensive and largest fundamental research AI center in China:::Nt For High energy physics Accelerator technologies and applications Synchrotron radiation technologies and applications 1000 employees, 650 physicists and engineers

2 Institute of High Energy Physics Comprehensive and largest fundamental research center in China For : – High energy physics – Accelerator technologies and applications – Synchrotron radiation technologies and applications 1000 employees, ~ 650 physicists and engineers

Beijing electron Positron Collider: beam energy 1-2.8GeV Physics Run: Luminosity 103]cms@1.89GeV, 5 month/year Synchrotron Radiation Run: 140mA @2.2 Gev, 3 month/year

Beijing Electron Positron Collider: beam energy 1 – 2.8 GeV Physics Run：Luminosity 1031cm-2 s -1 @ 1.89GeV, 5 month/year Synchrotron Radiation Run：140mA @ 2.2 GeV, 3 month/year

电子直线注入器 Linac

4 电子直线注入器 Linac

储存环 Storage ring

5 储存环 Storage Ring

北京谱仪 BES 北京谱仪 Beijing Spectrometer

6 北京谱仪 Beijing Spectrometer

BESII Detector (95-97 upgrade) Muon Counters Muon conters Solenoid Coil Main Main Drift Chamber Drift Chamber Vertex LUMI Chamber TOF Barrel Shower Counter Magnet Yoke Vertex Chamber Magnet Yoke JOH Counters Side view of the bes detector End view of the bes detector VC: Oxy=100 um TOF: or-=180 ps H counter: or=3 cm MDC: 0=250 um BSC: AE/E=22% 5.5c odeldx=8.4% =7.9mr B field: 0,4T △p/p=1.8V(1+p o,=2.3 cm Dead time/event: (10 ms

7 BESII Detector (95-97 upgrade) VC: xy = 100 m TOF: T = 180 ps  counter: r= 3 cm MDC: xy = 250 m BSC: E/E= 22 % z = 5.5 cm dE/dx= 8.4 % = 7.9 mr B field: 0.4 T p/p=1.8(1+p2 ) z = 2.3 cm Dead time/event: 〈10 ms

北京谱仪周际合作组 Political Map of the World, lune 1999 韩国(3) 美国 Korea University University of Hawaii 英国(1 Seoul National university University of Texas at Dallas ueeR- rsity aussi Chonbuk National univ Colorado state Unive rsity E Stanford Linear Accelerator Center T EO STATES 日本65) 中国(5) 中科院高能所 B我ALt 中国科技大学 Molave site 山东大学,浙江大学 cn- Tokyo Inst of Technology "s 华中师范大学 . -Miyazaki University 上海交通大学 KEK 北京大学,高等科技中心 武汉大学南开大学 河南师范大学 湖南大学辽宁大学 清华大学,四川大学

8 韩国 (3) Korea University Seoul National University Chonbuk National Univ. 日本 (5) Univ. of Tokyo Nikow University Tokyo Inst. of Technology Miyazaki University KEK 美国 (4) University of Hawaii University of Texas at Dallas Colorado State University Stanford Linear Accelerator Center 英国 (1) Queen Mary University 中国 (15) 中科院高能所 中国科技大学 山东大学, 浙江大学 华中师范大学 上海交通大学 北京大学, 高等科技中心 武汉大学., 南开大学. 河南师范大学 湖南大学, 辽宁大学. 清华大学, 四川大学 北京谱仪国际合作组

BES has the world largest Jhy and y samples lus: 2-5 GeVR scan, t threshold, 8 pby", 22.3pb-'Ds J/y 99,11-01.3 10 16 01,1-02.3 50 14 12 40 10 Mark DM2 BES BESI MARK Markl Crystal BESI BESIR Bal

9 BES has the world largest J/ and  samples plus: 2-5 GeV R scan,  threshold, 8 pb-1 “ , 22.3pb-1 Ds … J/ 106   106 0 10 20 30 40 50 60 MarkIII DM2 BESI BESII 0 2 4 6 8 10 12 14 16 MARKI MarkII Crystal Ball BESI BES II 01.11-02.3 99.11-01.3

Main physics results from bes o Precision measurement of t mass o Systematic study of y' decays: new VT decay suppressed modes and First measurement of B(V(2S)→t+) o measurement of fs from pure leptonic decay of Ds o Measure Br(Ds>o) in a model independent way.A: T .>120 entries in pdg from bEs 10

10 Main Physics Results from BES • Precision measurement of  mass . • Systematic study of  decays: new VT decay suppressed modes and First measurement of B((2S)→+-). • measurement of fDs from pure leptonic decay of Ds. • Measure Br(DS → ) in a model independent way. • > 120 entries in PDG from BES