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Charmless Baryonic Decays B -> pph Ping-Han Chu National Taiwan University 2003.6.16 Outline: 1.Introduction 2.Event Selection 3.Physics Results 4.Systematic.

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Presentation on theme: "Charmless Baryonic Decays B -> pph Ping-Han Chu National Taiwan University 2003.6.16 Outline: 1.Introduction 2.Event Selection 3.Physics Results 4.Systematic."— Presentation transcript:

1 Charmless Baryonic Decays B -> pph Ping-Han Chu National Taiwan University Outline: 1.Introduction 2.Event Selection 3.Physics Results 4.Systematic Error 5.Summary

2 Introdution The current-produced( J ) and transition( T ) diagrams for B -> ppK B p p K p p K B 1.B + -> ppK + 2.B + -> pp  + 3.B 0 -> ppK s 0 4.B + -> ppK* + ; (K* + -> K s 0  + ) 5.B 0 -> ppK* 0 ; (K* 0 -> K +  - ) J T Cited by Charmless three-body baryonic B decays Chun-Khiang Chua, Wei-Shu Hou, and Shang-Yuu Tsai, (PRD ) …These modes are of interest not just because of possibly large rates, but also by accessibility in detection…

3 KEKB Accelerator Asymmetric energy collision of electron = 8GeV, and positron = 3.5GeV Ring circumference : 3km RF frequency : 508MHz Target Luminosity = 1034 /cm^2/sec to produce more than 100 million B meson pairs in a year

4 KEKB Detector

5 Analyzed data 85 million BB events (78fb -1 ) at the  (4S) resonance recorded by the Belle before the summer 2002 are used in this analysis.

6 Event and reconstruction M bc dE M bc dE (All In CM frame)

7 Event Selection Track |dr|< 1Track|dz|< 3 PID> 0.6;KID> 0.6;  ID >0.6; Vchisq> 0;GoodKs> < mass Ks < < mass K * < 0.94 Signal Region: Abs(dE)<

8 Continuum suppression continuum background suppression Event topoplogy Modified Fox-Wolfram moments Fisher discriminants Angular distribution B flight direction e+ e- bb B B B B  thr jet-like qq events spherical BB events

9 Angular distribution; B flight direction e+ e- bb B B B B  thr

10 Modified Fox-Wolfram moments r2so, r3so, r4so, r2oo, r3oo, r4oo

11 Fisher discriminants The use of multiple measurements in taxonomic problems. By R.A. Fisher pp. Published in Annals Eugen.7: ,1936 NF7LR Fisher Parameters : costhr, spher, r2so, r4so,r2oo, r3oo, r4oo

12 Combined into a single Likelihood Ratio Likelihood method for signal determination(2-D fit)

13 Significance = 15.3

14 J/  CC Signal Region Sideband Region

15 MppBF(10^-6) Total

16 Significance = 6.7

17 Signal Region Sideband Region

18 MppBF(10^-6) Total

19 Significance = 5.1

20 J/  CC Signal Region Sideband Region

21 MppBF(10^-6) Total

22 Significance = 6.0

23 J/  Signal Region Sideband Region

24 MppBF(10^-6) Total

25 Significance = 3.14 Upper limit : 7.6*10 -6

26 K* + K* 0 D0D0

27 Calibrator

28 Compare with prevous result(exp7-exp13) Note: Mpp<3.4GeV

29 Acp Check PlusMinusAcp

30 Upper limit of Glueball Search 0.90*10^-6 C.L.90% Possible Hints and Search for Glueball Productin in Charmless Rare B Decays Chun-Khiang Chua, Wei-Shu Hou and Shang-Yuu Tsai (PLB544, 2002) 0.89*10^-6 C.L.90%

31 Systematic Error

32 Summary

33 Conclusion 1. spectrum can be compared with theorist's prediction. 2. Glueball search => giving upper limit. 3. The branching fraction of are different while we don't see this kind phenomenon in the relative modes, e.g., J/K and J/Ks, because of different isospin components.

34 Good Ks Momentum<0.50.5~1.5>1.5 Z distance<0.8<1.8<2.4 Fly length>0.08>0.22 dr>0.05>0.03>0.02 dd <0.3<0.1<0.03 Without GoodKs With GoodKs

35

36 J/  CC Signal Region Sideband Region

37 MppBF(10^-6) Total


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