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New CP Violation Results from B-meson Decays at Belle

New CP Violation Results from B-meson Decays at Belle. Yee Bob Hsiung National Taiwan University. December 1, 2004. 清華大學 Physics Colloquium. @. What is CP Violation?. CP Violation or Matter-Antimatter asymmetry C: charge conjugation P: space inversion T: Time reversal.

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New CP Violation Results from B-meson Decays at Belle

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

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

  3. Why Studying CP Violation?

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

  5. Cabbibo-Kobayashi-Maskawa Matrix

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

  7. Wolfenstein Parametrization

  8. CP Violating Phase

  9. The Kaon System

  10. NA48 @ CERN Fermilab

  11. Direct CP Violation DS = 1 Penguin Diagram

  12. Direct CP Violation: Re(e’/e)

  13. Kaon Decays and the SM JCP=2(Triangle Area) is the unique measure of CP-Violation in SM JCP = Im(Vud*VusVts*Vtd) ~ cosqc sinqcIm lt In the Wolfenstein parameterisation (l, A, h, r): Im lt = A2l5h, Re lt = A2l5r KL to 2pe’/e CP-Violation

  14. The Unitarity Triangle

  15. The Unitarity Triangle

  16. The B Factories: KEKB and SLAC-PEPII

  17. 感謝國科會九年來的支持！

  18. KEK(日本高能實驗室)鳥瞰圖 筑波山

  19. 253 fb-1 on Y(4S) 28 fb-1 below Y(4S) KEKB 加速器示意圖 8GeV electron 3.5GeV positron 正電子 電子 KEKB Collider 275M BB Lpeak = 1.39 x 1034 sec-1cm-2 @ 1.2A x 1.6A

  20. Belle The Billion $ Question: 測量B系統之CP破壞 B約兆分之一秒左右衰變 Red Hot ! 2001 J/yKS, p+p-, h’KS, fKS One B Decay CP Eigenstate Other B Decay Tag Flavor Measure Both Decay Vertex 台大都掌握中

  21. Belle Detector Aerogel Cherenkov cnt. n=1.015~1.030 SC solenoid 1.5T 3.5 GeVe+ CsI(Tl) 16X0 TOF conter 8 GeVe- Central Drift Chamber small cell +He/C2H5 Si vtx. det. 3(4) lyr. DSSD m / KL detection 14/15 lyr. RPC+Fe

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

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

  24. SVD1 SVD2 SVD Upgrade 2003 summer Impact parameter resolution rf Z • 1 MRad >20 MRad • 3 layers 4 layers • 23º<q<139º 17º<q<150º • Rbp = 2.0 cm 1.5 cm • Better I.P. resolutions _ _ 152M BB pairs with SVD1 + 123M BB pairs with SVD2

  25. Collaborate w/ Tokyo & Princeton etc. Belle SVD2 Upgrade NTU Contribution: TTM Trigger Timing Module SVD2under construction Install Summer 2003 FPGAs From 3-layers of SVD1 to 4-layers + self-tracking

  26. Students!

  27. SVD2: lifetime & Dmd SVD2 only D0p+, J/yK , D–p+, D*–p+/r+, D*ln Belle preliminary SVD1 _ (152M BB) SVD2 _ (123M BB) (stat) [ps] (stat) [ps] (stat) [ps-1] [Belle-conf-0436] New detector resolution is well understood

  28. W _ _ s/d Vtb t K/p+ W u s/d g K/p+ u u Vub 0 d B _ _ G(Bf ) - G(Bf ) p- p- d d u d d _ _ G(Bf ) + G(Bf ) ACP = 0 d B b b Vts/d Vus/d   B Kp/pp Tree Penguin • Simplest charmless rare decay modes • Tree - Penguin interference Direct CP Violation Key prediction of Kobayashi-Maskawa model Understanding of Penguin Anomaly (New Physics)

  29. 275M BB New ACP(B0 K+p-) _ B0 K-p+ B0 K+p- Signal: 2139 53 [submitted to PRL] ACP = -0.101  0.025  0.005 3.9ssignificance [PID efficiency bias correction: dA = -0.01  0.004] 2ndEvidence for DCPV at Belle ! [A(p+p-) 3.2s]

  30. 152M BB App Spp B0gp+p CPV Result Direct CPV 3.2s good tag Dt (ps) App = +0.58 0.15(stat) 0.07(syst) Spp = 1.00 0.21(stat) 0.07(syst) [PRL93,021801 (2004)]

  31. 275M BB New ACP(B  K+p0 ) Kp0 : 728 53 ACP(Kp0) = 0.04  0.05  0.02 hint thatACP(K+p- ) ¹ACP(Kp0 ) ? (2.4s) d p0 Large EW penguin (Z0) ? New Physics ? _ d B- b s K- u u

  32. 275M BB, New Observation of B0p0p0 Key mode for f2(a) in Bgpp CPV isospin analysis Evidence (LP03)Observation ! Signal: 82  16 (6.0s) B = (2.32  ) x 10-6 0.44 0.48 0.22 0.18 Large Br established Mbc [Belle-conf-0406] ACP = 0.44  0.51  0.17 0.16 uses same Flavor-tagging as TCPV analysis 1st measurement !

  33. aEW Radiative & EW Penguins Loops Sensitive to New Physics l+ l- b  sl+l- penguin ~1/100 b  sg penguin Br, ACP ~SM b  dg penguin K*g TCPV

  34. 275M BB B  K(*) l+l- [Belle-conf-0415] LP03: B Xsll, K(*)ll : Belle/BaBar Br, ACP ~SM update >10s signals 82 11 signals 79 10 signals B (Kll)= (5.50 0.27  0.02) 0.75 0.70 B (K*ll)= (16.5  0.9  0.4) 2.3 2.2 x 10-7 Mbc q2 (GeV2/c2)

  35. * V V tb ts Time-dependent CP Violation (TCPV) B0 fCP = fCP B0 mixing B0 B0 ACP (Dt) = S sin(DmDt) + A cos (DmDt) Mixing induced CPV Direct CPV f + SM: bs Penguin phase = J/yKS(bc) + New Physics with New Phase Sbs¹ sin2f1 , Acan¹ 0 Sbs=sin2f1,A=0

  36. Time Dependent CP Asymmetry S= -xfsin2f1: SM prediction A= 0 or |l| = 1  No direct CPV Af q l = hf CP CP p Af Inputs: xf = -1, S = 0.6 A= 0.0 CP

  37. b  sqq Penguin CPV - Belle @LP03 (140 fb-1) [PRL 91, 261602 (2003)] B0fKs B0 J/yKsetc sin2f1=0.728  0.06 “sin2f1”= -0.96  0.51 3.5s deviation from the SM !

  38. 275M BB pB* B0f K0 fKS Nsig=139 14 fKL purity 0.63 Nsig= 36 15 purity 0.17 Similar to J/yKL recon. + sophisticated continuum suppression includes Ks p0po (Nsig=13 5)

  39. B0f KS : Mass & Helicity f Helicity Mass bkg

  40. 275M BB S = 0.73 fit B0f K0 : CPV Result f K0 Good tags Poor tags Good tags fKS+fKL:S(fK0) = +0.06 0.330.09 A(fK0) = +0.080.220.09 ~2s away from SM

  41. Checks: sin2f1 (B0J/y KS/L) Validation of new data sample (SVD2) _ SVD1: 152M BB SVD1 S = 0.696  0.061 (stat) A = 0.011  0.043 (stat) Good tags _ SVD2: 123M BB SVD2 S = 0.629  0.069 (stat) A = 0.035  0.044 (stat) Good tags Dt (ps) f K0 ~2.3s SVD1: S = -0.68  0.46 A = -0.02  0.28 SVD2: S = +0.78  0.45 A =+0.17  0.33 many systematic checks, all ok 

  42. History of “sin2f1” with fK0 _ sin2f1 from ccs “sin2f1” BABAR Belle 106

  43. 275M BB S = 0.73 fit B0h’KS& K+K-KS high statistics modes h’KS K+K-KS (fexcluded) h’rg, hp+p- (hgg, p+p-p0) Nsig=399 28 Nsig=512 27 purity 0.56 purity 0.61 CP=+1: 1.03 0.15 0.05 Raw Asymmetry Raw Asymmetry Good tags Good tags “sin2f1” (~0.5s @SM) (~1.0s @SM) 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 0.17 0.0

  44. 275M BB S = 0.73 fit B0wKS& f0(980)KS wKS f0(980)KS additional modes Nsig=31 7 Nsig=94 14 purity 0.53 purity 0.56 Raw Asymmetry Raw Asymmetry Good tags Good tags “sin2f1” (~0s @SM) (~2.9s @SM) 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 0.13 0.16

  45. 275M BB Summary of b  sqq CPV - “sin2f1” 2.4 (A: consistent with 0)

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

  47. 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 B0 K+p-(~-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 (1036 SuperB) machine, better experiments at JHF-JPARC and new physics studies/searches in the LHC and/or LC era

  48. Future Prospect of f1 (b) Measurements

  49. Future Prospect of f2 (a) Measurements 0.5 ab-1 5 ab-1 50 ab-1 Going for Super B factory

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