1. New CP Violation Results from B-meson Decays at Belle December 1, 2004 Yee Bob Hsiung National Taiwan University @ 清華大學 Physics Colloquium

2. 2 What is CP Violation? CP Violation or Matter-Antimatter asymmetry C: charge conjugation P: space inversion T: Time reversal

3. 3 Why Studying CP Violation?

4. 4 CP Violation in the Standard Model CP violation (  ) was first discovered in Kaon decays (1964) 33 years later (1997) “direct” CP violation was observed in K to 2  decays (  ’  ) CP violation in the B decays can now be studied in both Belle(KEK) and BaBar(SLAC) in detail

5. 5 Cabbibo-Kobayashi-Maskawa Matrix

6. 6 CP-Violation in Standard Model J CP =2  (Triangle Area) Is the unique measure of CP-Violation in SM N g =3 N phase =1  CP-Violation Possible A phase in the quark-quark current leads to CP-Violation (Kobayashi, Maskawa, 1973) 6 unitarity relations ( triangles in the complex plane)

7. 7 Wolfenstein Parametrization

8. 8 CP Violating Phase

9. 9 The Kaon System

10. 10 NA48 @ CERN Fermilab

11. 11 Penguin Diagram  S = 1 Direct CP Violation

12. 12 Direct CP Violation: Re(  ’/  )

13. 13 Kaon Decays and the SM J CP =2  (Triangle Area) is the unique measure of CP-Violation in SM J CP = Im(V ud * V us V ts * V td ) ~ cos  c sin  c Im  t In the Wolfenstein parameterisation (, A, ,  ): Im t = A 2 5 , Re t = A 2 5  CP-Violation K L to 2   ’/ 

14. 14 The Unitarity Triangle

15. 15 The Unitarity Triangle

16. 16

17. 17 The B Factories: KEKB and SLAC-PEPII

18. 18 感謝國科會九年來的支持！

19. 19 KEK ( 日本高能實驗室 ) 鳥瞰圖 筑波山

20. 20 KEKB 加速器示意圖 8 GeV electron3.5 GeV positron KEKB Collider 電子 正電子 @ 1.2A x 1.6A @ 1.2A x 1.6A L peak = 1.39 x 10 34 sec -1 cm -2 275M BB 253 fb -1 on Y(4S) 28 fb -1 below Y(4S)

21. 21 The Billion $ Question: 測量 B 系統之 CP 破 壞 One B Decay CP Eigenstate Other B Decay Tag Flavor Measure Both Decay Vertex Belle J/yK S, p + p -, h ’ K S, fK S Red Hot ! 台大都掌握中 2001 B 約兆分之一秒左右衰變

22. 22 Belle Detector  / K L detection 14/15 lyr. RPC+Fe C entral D rift C hamber small cell +He/C 2 H 5 CsI(Tl) 16X 0 Aerogel Cherenkov cnt. n=1.015~1.030 Si vtx. det. 3(4) lyr. DSSD TOF conter SC solenoid 1.5T 8 GeV e  3.5 GeV e 

23. 23 B-meson Reconstruction Energy difference: Beam-constrained mass:  Utilize special Kinematics at Y(4S) (ES)

24. 24 Continuum Suppression e+e+ e-e- e+e+ e-e- qq Signal B Other B Dominant Background for rare decays: Continuum Jet-like BB spherical e + e   qq “continuum” (~3x BB) To suppress: use event shape variables   continuum Y (4S)

25. 25 SVD Upgrade SVD1SVD2 1 MRad  >20 MRad 3 layers  4 layers 23º<  <139º  17º<  <150º R bp = 2.0 cm  1.5 cm Better I.P. resolutions 2003 summer Impact parameter resolution rr Z 152M BB pairs with SVD1 + 123M BB pairs with SVD2 _ _

26. 26 Belle SVD2 Upgrade Collaborate w/ Tokyo & Princeton etc. SVD2 under construction Install Summer 2003 TTM NTU Contribution: TTM Trigger Timing Module From 3-layers of SVD1 to 4-layers self-tracking 4-layers + self-tracking FPGAs

27. 27 Students!

28. 28 SVD2: lifetime &  m d [ps] [ps  1 ] SVD1 _ (152M BB) SVD2 _ (123M BB) New detector resolution is well understood SVD2 only Belle preliminary D 0  +, J/  K , D –  +, D* –  + /  +, D*l (stat) [Belle-conf-0436]

29. 29 B   Penguin d b d _ s/d u u W B 0d0d --  + V us/d  V ub Tree Simplest charmless rare decay modes Tree - Penguin interference  Direct CP Violation Key prediction of Kobayashi-Maskawa model Key prediction of Kobayashi-Maskawa model Understanding of Penguin _ _  (B  f )  (B  f ) _ _  (B  f )  (B  f ) A CP = Anomaly (New Physics) B 0d0d d b d u u W g  + -- V ts/d  V tb t s/d

30. 30 A CP (B 0  K    ) 2 nd Evidence for DCPV at Belle ! [ A (     ) 3.2  ] A CP = -0.101  0.025  0.005 [PID efficiency bias correction:  A = -0.01  0.004] 275M BB New 3.9  significance [submitted to PRL] B 0  K    _ B 0  K    Signal: 2139  53

31. 31 B 0   +   CPV Result A  = +0.58  0.15(stat)  0.07(syst) S  =  1.00  0.21(stat)  0.07(syst) S  A   t (ps) Direct CPV  3.2  [PRL93,021801 (2004)] good tag 152M BB

32. 32 A CP (B  K    ) A CP ( K    ) = 0.04  0.05  0.02 275M BB New K    : 728  53 hint that A CP ( K    )  A CP ( K    ) ? (2.4  ) Large EW penguin (Z 0 ) ? New Physics ? _d_d d  KK u u BB sb

33. 33 Observation of B 0   0  0 275M BB, New Evidence (LP03)  Observation ! B = (2.32   ) x 10 -6 Large Br established Signal: 82  16 (6.0  ) A CP = 0.44  0.51  uses same Flavor-tagging as TCPV analysis 1 st measurement ! M bc [Belle-conf-0406] Key mode for  2 (  ) in B   CPV isospin analysis 0.44 0.48 0.22 0.18 0.17 0.16

34. 34 Radiative & EW Penguins  EW ~1/100 Loops  Sensitive to New Physics K*  TCPV Br, A CP ~SM b  s  penguin b  sl + l  penguin b  d  penguin l+l+ ll

35. 35 B  K (*) l + l  79  10 signals 82  11 signals [Belle-conf-0415] B (Kll)= (5.50   0.27  0.02) 275M BB 0.75 0.70 B (K*ll)= (16.5   0.9  0.4 ) 2.3 2.2 >10  signals update LP03: B  X s ll, K (*) ll : Belle/BaBar Br, A CP ~SM x 10 -7 q 2 (GeV 2 /c 2 ) M bc

36. 36 Time-dependent CP Violation B0B0 B0B0 mixing = B0B0 B0B0  + + New Physics with New Phase S b  s  sin2  1, A can  0 S b  s =sin2  1, A =0 SM: b  s Penguin phase = J/  K S (b  c) tstb VV  Mixing induced CPV Direct CPV A CP (  t) = S sin(  m  t) + A cos (  m  t) (TCPV) f CP

37. 37 Time Dependent CP Asymmetry S =  f sin2  1 : SM prediction A = 0 or | | = 1  No direct CPV Inputs:  f =  1,S = 0.6 A = 0.0  f q p AfAf AfAf CP

38. 38 b  sqq Penguin CPV Belle @LP03 (140 fb -1 ) “sin2  1 ”=  0.96  0.51 B 0   Ks sin2  1 =0.728  0.06 B 0  J/  Ks etc 3.5  deviation from the SM ! - - [PRL 91, 261602 (2003)]

39. 39 B 0   K 0 Similar to J/  K L recon. + sophisticated continuum suppression includes Ks      (Nsig=13  5) KSKS Nsig=139  14 purity 0.63 pB*pB* Nsig= 36  15 KLKL purity 0.17 275M BB

40. 40 B 0   K S : Mass & Helicity  Helicity bkg Mass

41. 41 B 0   K 0 : CPV Result  K 0  K S +  K L : S (  K 0 ) = +0.06  0.33  0.09 A (  K 0 ) = +0.08  0.22  0.09 ~2  away from SM  K S +  K L : S (  K 0 ) = +0.06  0.33  0.09 A (  K 0 ) = +0.08  0.22  0.09 ~2  away from SM Good tags Poor tags S = 0.73 fit Good tags 275M BB

42. 42 Checks: sin2  1 (B 0  J/  K S/L ) SVD1: 152M BB  t (ps) Good tags SVD1 Validation of new data sample (SVD2) SVD2: 123M BB Good tags SVD2 _ S = 0.696  0.061 (stat) A = 0.011  0.043 (stat) S = 0.696  0.061 (stat) A = 0.011  0.043 (stat) S = 0.629  0.069 (stat) A = 0.035  0.044 (stat) S = 0.629  0.069 (stat) A = 0.035  0.044 (stat) _ SVD2: S = +0.78  0.45 A =+0.17  0.33 SVD1: S =  0.68  0.46 A =  0.02  0.28  many systematic checks, all ok ~2.3   K 0

43. 43 History of “sin2  1 ” with  K 0  10 6 Belle B A B AR _ sin2  1 from ccs “sin2  1 ”

44. 44 B 0  ’K S  K  K  K S  ’K S KKKSKKKS Nsig=512  27 purity 0.61 Nsig=399  28 purity 0.56 S = +0.65  0.18  0.04  S = +0.49  0.18  0.04 (  ) A =  0.19  0.11  0.05 A =  0.08  0.12  0.07 CP=+1: 1.03  0.15  0.05 “sin2  1 ” Raw Asymmetry Good tags S = 0.73 fit 0.17 0.0 Raw Asymmetry (~0.5  @SM)(~1.0  @SM) high statistics modes (  excluded)  ’       (  ,       ) 275M BB

45. 45 B 0  K S  f 0 (980)K S KSKS additional modes Nsig=31  7 purity 0.56 Nsig=94  14 purity 0.53 f 0 (980)K S S = +0.75  0.64   S =  0.47  0.41  0.08 A =  0.26  0.48  0.15 A =  0.39  0.27  0.08 “sin2  1 ” Raw Asymmetry Good tags S = 0.73 fit 0.13 0.16 Good tags Raw Asymmetry (~2.9  @SM)(~0  @SM) 275M BB

46. 46 Summary of b  sqq CPV - - 2.4  “sin2  1 ” 275M BB ( A : consistent with 0)

47. 47 Charmless B Br Summary HFAG P.Chang (NTU) J.Alexander (Cornell) J.Smith (Colorado) Complete list (other Br & A CP ) http://www.slac.stanford.edu/xorg/hfag/rare/ x10 -6

48. 48 Summary CP Violation has been well established in the kaon system, both “direct” and “indirect” and now being extensively explored in B-meson system Evidence of “direct” CP violation has been seen in B   K +   (~-10%), search for new physics beyond the Standard Model will continue in b  s penguin modes and 3 angles measurement of unitarity triangle. However, the origin of CP violation may well be uncovered from both K and B system in the next 5-10 years by comparing the (in)consistency of the unitarity triangles There maybe hints of new physics beyond the SM in the K and B system which will call for high luminosity (10 36 SuperB) machine, better experiments at JHF- JPARC and new physics studies/searches in the LHC and/or LC era

49. 49 Future Prospect of    Measurements

50. 50 Future Prospect of    Measurements  ab -1  ab -1  ab -1 Going for Super B factory

51. 51 The End