1. 08/31/02PID Workshop@Nagoya1 TOP Counter R & D Status — PID and Physics — TOP Counter — R&D Status Katsumi Senyo Nagoya University

2. 08/31/02PID Workshop@Nagoya2 PID and Physics B->  DK/D  85.2±10.1 12.3±3.9 0.4±3.8 B->K  /  Preliminary!

3. 08/31/02PID Workshop@Nagoya3 TOP Counter Performance(K/pi separation) TOP ideal performance: Better than sig. 4

4. 08/31/02PID Workshop@Nagoya4 PID and Physics Current PID devices TOP(expected perf.)

5. 08/31/02PID Workshop@Nagoya5 Time Of Propagation(TOP) Counter x z y 20mm PMTs Fused silica(n=1.47) Reflection mirror 200mm A few meters

6. 08/31/02PID Workshop@Nagoya6 TOP Counter MAPMT Crystal Bar 1m

7. 08/31/02PID Workshop@Nagoya7 PID Devices (3)  Cerenkov Counter A charged particle velocity greater than the (local phase) velocity of light →Radiating Cerenkov light Cerenkov cone half angle: cos  = 1 /n 

8. 08/31/02PID Workshop@Nagoya8 DIRC(Detection of Internally Reflected Cherenkov light) and TOP Counter DIRC: Radiation angle -> X-Y position 1m1m TOP: Radiation angle -> Prop. Time-X position Both TOP and DIRC give a hyperbolic projection image of Cherenkov light. Time or

9. 08/31/02PID Workshop@Nagoya9 TOP Counter L y z qzqz PMT Radiation anglePropagation time Short Propagation time:  - like Long Propagation time : K - like

10. 08/31/02PID Workshop@Nagoya10  What’s problem in DIRC? DIRC (cont.) Huge Stand-off Volume Is really such a dead volume needed? ~4m

11. 08/31/02PID Workshop@Nagoya11 TOP Counter  The 3 dimension information of the Cerenkov cone is resolved with time and x position at the cross section of the fused silica. １ ２ ３ Readout Propagation times of １,2,3 are different

12. 08/31/02PID Workshop@Nagoya12 TOP Counter TOP x （ mm ） TOP x （ mm ） （ ns ） 30 photons observed in typical case. Unfolding

13. 08/31/02PID Workshop@Nagoya13 Key Issues on TOP Counter R & D  Good timing resolution(~100ps) on a single photon measurement w/ position-sensitive(~1mm) MAPMT.  Precise fused silica bar production on geometry and smoothness (~ Å).  Sophisticated analysis method.

14. 08/31/02PID Workshop@Nagoya14 MAPMT R & D HPK R5900-U-L16 – Transit Time Spread~ ７５ ps – channel width １ mm Collaboration w/ HPK Insensitive region

15. 08/31/02PID Workshop@Nagoya15 Fused Silica bar R & D Δt ~150ps even after 4m transition Improved Polish and Finish Previous Polish

16. 08/31/02PID Workshop@Nagoya16 Time v.s. X plot (Beam test result) 2.5GeV/c pion @KEK-PS pi2 line on Nov,2001. Good relation of photon propagation time and X position at the edge is observed as expected. Preliminary! 200k events concentrated plot

17. 08/31/02PID Workshop@Nagoya17 TOP Counter – Installed in Super-Belle   （ 4s ） → BB   Installing Belle detector… r = 1m 30  < q < 140  barrel region P(K/  )

18. 08/31/02PID Workshop@Nagoya18 Bar TOP v.s. Mirror TOP(MC Study) Separability > 4 in whole coverage of Super Belle

19. 08/31/02PID Workshop@Nagoya19 Summary  TOP Counter is a promising PID device at next-generation B factories.  R & D is in good shape.  Beam test results will be performed on Nov.

20. 08/31/02PID Workshop@Nagoya20 DIRC (cont.)

21. 08/31/02PID Workshop@Nagoya21 PID and B Physics  Flavor Tagging － Determine a flavor of B P K < 1.5 GeV/c  Rare Decays including K and    －  B->K  /  DK/D    2.0 < P K < 4.0 GeV/c

22. 08/31/02PID Workshop@Nagoya22 PID System at Belle

23. 08/31/02PID Workshop@Nagoya23 DIRC Improvement  Focusing DIRC  Photon Propagation Time SLAC-PUB-8989 The Next Generation of Internally Reflected Imaging Counters, Sep.2001

24. 08/31/02PID Workshop@Nagoya24 TOP Counter (cont.) – HPK R5900-U-L16 time res. ７５ ps channel width １ mm 30 photons observed in typical case

25. 08/31/02PID Workshop@Nagoya25 TOP Counter(Bar width) 22 cc cc cc cc K  K  K  K  50mm100mm150mm200mm The bar width should be 200 mm or larger in current analysis scheme.

26. 08/31/02PID Workshop@Nagoya26 TOP Counter - Application  Detected #Photon : 30~100

27. 08/31/02PID Workshop@Nagoya27 TOP Counter - Separability S = 10  Mom. p = 4GeV/c,  ＝ 90° （ L = 2m ）

28. 08/31/02PID Workshop@Nagoya28 Separability for B-> 