1. July 2000Results from BELLE1 IV th Rencontres du Vietnam Hanoi, Vietnam Daniel Marlow BELLE Princeton University July 22, 2000

2. July 2000Results from BELLE2 Initial Physics Goal Our principal physics goal is to test the KM picture of CP violation by measuring the angle (aka ) of the unitarity triangle. In phase II, we will seek to measure and ( ).

3. July 2000Results from BELLE3 Existing Constraints Existing measurements of mixing and limit the allowed region in the plane. F. Parodi et al.

4. July 2000Results from BELLE4 The Measurement tag CP Need to: Measure momenta ID leptons & K’s Measure vertices

5. July 2000Results from BELLE5 The Measurement The time-dependent asymmetry appears mainly as a mean shift in the distribution between events tagged as decays and events tagged as decays.

6. July 2000Results from BELLE6 The KEK-B Asymmetric Collider KEK-B is similar to PEP- II in many ways, although there is a (potentially) important difference in the way in which the beams are brought into collision.

7. July 2000Results from BELLE7 Recent Run Snapshot Snapshot chosen at randomly selected time.

8. July 2000Results from BELLE8 Daily Luminosity History pb -1 /day pb -1 date 80 pb -1 /day (recently down a bit) 6.2 fb -1 total

9. July 2000Results from BELLE9 The Magnet

10. July 2000Results from BELLE10 About 10 Countries, 50 Institutes, & 250 People The BELLE Collaboration

11. July 2000Results from BELLE11 The Silicon Vertex Detector (SVD) Sensors: HPK DS640 (DSSD’s) Readout: VA1 chip from IDEAS

12. July 2000Results from BELLE12 SVD Performance CDC/SVD Track Matching:

13. July 2000Results from BELLE13 CDC Performance (Cosmic Rays)

14. July 2000Results from BELLE14 CDC Performance

15. July 2000Results from BELLE15 Particle ID (dE/dx, ToF, & Aerogel)

16. July 2000Results from BELLE16 CsI EM Calorimeter Performance

17. July 2000Results from BELLE17 Muon Detection Note that there are no missing hits in the layers of the muon system, except at the sector edges, where there is support structure.

18. July 2000Results from BELLE18 Detection

19. July 2000Results from BELLE19 Inclusive Electron Spectrum

20. July 2000Results from BELLE20 Beam Constrained Mass

21. July 2000Results from BELLE21 D 0 Mass Plot 1.80 1.84 1.86 1.90 To warm up our analysis machinery, we have studied charm lifetimes.

22. July 2000Results from BELLE22 D 0 Lifetime 1000 3000 -1000 -3000 1000 3000 -1000 -3000

23. July 2000Results from BELLE23 D S Lifetimes

24. July 2000Results from BELLE24 Dilepton Mass Spectra 5.5 fb -1

25. July 2000Results from BELLE25 Exclusive Mode Reconstruction 4.3 fb -1

26. July 2000Results from BELLE26 Exclusive Mode Reconstruction 4.3 fb -1

27. July 2000Results from BELLE27 Exclusive Mode Reconstruction We can also detect events by detecting the direction of the K L. This mode complements the mode, but has more background. K L hits KLKL

28. July 2000Results from BELLE28 Exclusive Mode Reconstruction MC: histogram Data: points 5.2 fb -1

29. July 2000Results from BELLE29 Reconstruction The mode represents a background to the more interesting Cabbibo suppressed mode

30. July 2000Results from BELLE30 Reconstruction Particle ID is an effective tool in pulling the signal out from underneath the background. Kaon probability

31. July 2000Results from BELLE31 Reconstruction Particle ID is an effective tool in pulling the signal out from underneath the background.

32. July 2000Results from BELLE32 Neutral B Mixing from Dileptons

33. July 2000Results from BELLE33 B Mixing from Dileptons Preliminary

34. July 2000Results from BELLE34 Summary and Conclusions BELLE has accumulated ~6.2 fb -1 of luminosity in its first ~year of operation. The detector is working well and the analysis machinery is beginning to produce results that are competitive with previous measurements. One can hope for further increases in luminosity in the months to come. Look for more results at Osaka.