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(2S) radiative and hadronic transitions at BES

(2S) radiative and hadronic transitions at BES. Zhiyong Wang IHEP, Beijing ,China for the BES Collaboration. International Workshop on Heavy Quarkonium October 12-15, 2004 , IHEP Beijing. BESII Detector. VC:  xy = 100  m TOF:  T = 180 ps  counter:  r  = 3 cm

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(2S) radiative and hadronic transitions at BES

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  1. (2S) radiative and hadronic transitions at BES Zhiyong Wang IHEP, Beijing ,China for the BES Collaboration International Workshop on Heavy Quarkonium October 12-15, 2004 , IHEP Beijing

  2. BESII Detector VC: xy = 100 m TOF: T = 180 ps counter: r= 3 cm MDC: xy = 220 m BSC: E/E= 22 % z = 5.5 cm dE/dx=8.5 % = 7.9 mr B field: 0.4 T p/p=1.7%(1+p2) z = 3.1 cm

  3. World J/ and (2S) Samples (×106) Largest from BES J/ (2S) 14 M 58 M 2002 2001

  4. outline  (2S)0J/,0 (2S)J/, (2S)c1 , c1 J/ (2S)c2 , c2 J/ J/ (BES-II data) J/e+e，+  (2S)J/ (2S)J/ (2S)c1 , c1 J/ (2S)c2 , c2 J/ X+J/ (BES-I data) J/+

  5. Charmonium System

  6. ' J/ • Measure: • '  oJ/,J/ • ' cJ  J/ (J=1,2) • Old measurements disagree. • B(’  oJ/)very crude: • (23 evts at CBAL, 7 evts at MRK2). • Theoretical predictions for charmonium hadronic transition amplitudes can be tested by high statistics measurements.

  7. ' J/ Previous experiment results((2S)…)

  8. ' J/ J/ cJ  J/ Take + final state as an example MC 0J/ J/e+e or +, 5C (J/ mass) kinematic fit is applied! BKG from 00J/

  9. ' J/  (2S) →cJ→ J/ (2S) → 0J/ e+e e+e +  (2S) →cJ→ J/ (2S) → J/ + e+e +

  10. ' J/ PDG04 2.67 ± 0.15 1.30 ± 0.08

  11. ' J/ BES most accurate c1 J/ c2 oJ/ BES BES measures the BRs with high precision! Phys.Rev.D70:012006,2004

  12. Discussions ’ J/ PCAC [G. A. Miller, Phys. Rep. 194,1(1990)]: Casalbuoni et al: give an improved expression [PLB 309,163(1993)], but Aand Bare unknown BES result:R=0.048±0.007 B/A=-1.420.12 B/A=-3.11  0.15 QCD Multipole Expansion & BTG potential model [Y. P. Kuang, PRD24, 2874(1981), ibid. 37, 1210(1988) BES (+PDG for ): R<0.0098 R<0.0065

  13. ' XJ/ M. Suzuki, PRD63, 054021, (2001). Y. F. Gu and X. H. Li, PRD63, 114019 (2001). B((2S) hadrons)/B(J/  hadrons) = B((2S)  ggg + gg)/B(J/  ggg + gg) = 0.23 ± 0.07 Disagrees with “12 % Rule” Important to measure ’  X J/ and components. Method – identify J/+ Select muons. 1 C fit to mJ/ determine mX pX p μ+ p μ- pJ/

  14. ' XJ/ Inclusive measurement – use events that satisfy 1 C fit. J/ peak • Fit distribution: • background (mμμ< 3.4) • 1307 events • signal 44498 events Background e+ e-   μ+μ- and e+ e-  ’   μ+ μ-

  15. ' XJ/ Exclusive measurements To separate ’ 00J/ and +J/, plot mX for no extra charged tracks and for extra charged tracks. Fit two simultaneously with component shapes. 2 < 7 no extra extra + 00 η c2 c1 η backgrd

  16. ' XJ/ Determine ratio of branching ratios to B(’  + -J/ ) to cancel systematic errors. Constrain C2/c1 since shapes similar. Results measured Phys.Rev.D70:012003,2004 BESI – 4 million (2S) events.

  17. Summary • The precision of B((2S)0J/, 00J/ J/,c1,2) are improved, especially for B((2S)0J/) • Some theoretical models are tested by our new measurement results Thank you ! 谢谢!

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