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CP VIOLATION at B-factories

CP VIOLATION at B-factories. A.Bondar (Budker INP,Novosibirsk). Measurements of large CPV in b c c s modes Search for New Physics: CPV in bs penguin modes Measurement of CPV in B p + p – See also Today A.Mihalyi “ Recent results on the CKM angle α from BABAR ”

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CP VIOLATION at B-factories

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  1. CP VIOLATION at B-factories A.Bondar (Budker INP,Novosibirsk) Measurements of large CPV in bc c s modes Search for New Physics: CPV in bs penguin modes Measurement of CPV in Bp+p – See also Today A.Mihalyi “Recent results on the CKM angle α from BABAR” New method of the f3 measurement in BD0K based on Dalitz plot analysis of the three body D0KSp+p –decay See also Today M. Legendre “Status and prospects for the measurement of angle γ” T. Gershon “Measurement of φ3 using B– to DK– with D to Ksπ+π–” DAFNE04 Frascati June 7, 2004

  2. quark decay i gFVij j quark decay i gFVij* j CP • l = 0.2235±0.0033A =0.81±0.08 |r-ih|=0.36±0.09 |1-r-ih|= 0.79±0.19 The Weak Decays of Quarks • Coupling strength at decay vertex : gFVij • universal Fermi weak coupling : gF • Vij : quark-mixing matrix elements • CKM matrix : • unitarity : Vji*Vjk=dik • explicit parametrization (Wolfenstein) • complex phase leads to different bu and td amplitudes for quarks and anti-quarks. DAFNE04 Frascati June 7, 2004

  3. B0 pp B0rp (a) B0 D(*)p B+DK (g) (b) B0 J/yKs B0fKs B0D(*)D(*) The B Unitarity Triangle Using orthogonality relation DAFNE04 Frascati June 7, 2004

  4. CKM CP phenomenology • CP violation arises from the interference of two amplitudes with different phases. • Mixing induced CP violation : Indirect CPV • Decay amplitudes asymmetry: Direct CPV • Single CKM phase = unique source of CPV ? • It is difficult for CKM CPV to explain the observed matter/antimatter asymmetry in the universe. • It is needed to search for Beyond SM ! DAFNE04 Frascati June 7, 2004

  5. Direct CP violation param. z Mixing induced CPV param. Time-dependent CP violation If either S or A is non-zero, B fCP has CP asymmetry. DAFNE04 Frascati June 7, 2004

  6. BELLE detector ~350 scientists, 55 institutions KEKB & BELLE KEKB Collider 3.5GeV e+ & 8GeV e-Asymmetric Collider 3km circumference, 11mrad crossing angle • L= 1.3 x 1034 cm–2s–1 (world record) Ldt = 266 fb–1 @{Y(4S)+off(~10%)} (140fb-1 : 1.52 x 108 ) DAFNE04 Frascati June 7, 2004

  7. e- (9 GeV) PEPII & BABAR e+ (3 GeV) PEPII Collider BABAR Detector Superconducting Coil (1.5T) 3GeV e+ & 9GeV e-Asymmetric Collider L= 0.92 x 1034 cm–2s–1 Ldt = 214 fb–1 @{Y(4S)+off(~10%)} Silicon Vertex Tracker Drift Chamber CsI(Tl) Calorimeter Cherenkov Detector (DIRC) Instrumented Flux Return DAFNE04 Frascati June 7, 2004

  8. How to measure CP violation ? BCP e-: 8.0 GeV e+: 3.5 GeV fCP e- e+ ¡(4S) bg ~ 0.425 DzcbgtB ~ 200 mm Btag Flavor tag Dz • 4 steps toward the CP violation measurement • Reconstruct BfCP decays • Determine the flavor of Btag • Measure proper-time interval : Dt • Evaluate asymmetry from the obtained Dt distributions DAFNE04 Frascati June 7, 2004

  9. sin2f1 :bccs hep-ex/0308036 BaBar 81 fb-1: sin(2φ1) =0.741±0.067±0.033 DAFNE04 Frascati June 7, 2004

  10. cos2f1 from B  J/y(Kp)0 Moriond04, M.Verderi DAFNE04 Frascati June 7, 2004

  11. cos2f1 from B  J/y(Kp)0 DAFNE04 Frascati June 7, 2004

  12. cos2f1 from B  J/y(Kp)0 DAFNE04 Frascati June 7, 2004

  13. In the SM, for pure bs penguin transition modes sin2f1eff = sin2f1(BJ/yKS) Non-Standard-Model particles could appear in the penguin loop, modifying rate and/or CP asymmetry DAFNE04 Frascati June 7, 2004

  14. L = 108 fb-1 hep-ex/0406005 DAFNE04 Frascati June 7, 2004

  15. L = 111 fb-1 hep-ex/0406005 BELLE PRD 60, 012001(2004) DAFNE04 Frascati June 7, 2004

  16. sin2f1 Summary DAFNE04 Frascati June 7, 2004

  17. p+ d W+ b u p- B0 d d B0 d b p+ t u g B0 u p- d d Points of B0 π+π–decay • sensitive to CKM angle f2 • direct CP violation may also occur because of interference between • b  u tree amplitude and • b  d penguin amplitude • It’s very important to check the KM matrix by other measurements. DAFNE04 Frascati June 7, 2004

  18. Constraints on the CKM angle f2 convention taken from M.Gronau and J.L.Rosner Phys. Rev. D65, 093012 (2002) 4 parameters Strong phase difference |P/T| 0.15-0.45 (representative) Theory ~0.3 f1 23.7 deg (Belle & BaBar combined) DAFNE04 Frascati June 7, 2004

  19. L = 140 fb-1 High Quality Events Low Quality Events sin2f2 : buud,B0p+p- DAFNE04 Frascati June 7, 2004

  20. Observation of CP violation (5.2s) Evidence for direct CP violation 3.2s for App=0 and any Spp App 3.3s for “superweak” case Spp Significance Feldman-Cousins Analysis hep-ex/0401029 DAFNE04 Frascati June 7, 2004

  21. History ofAppand Spp Belle This result Belle 140fb1 BaBar Difference still at ~2.0s level DAFNE04 Frascati June 7, 2004

  22. Belle 140fb1 Constraint onf2and|P/T| |P/T| 3s 3s 1s 2s 2s 1s f2 (deg.) f2 (deg.) |P|/(|T|+|P|) d (deg.) |P/T| > 0.17 [95.5% C.L. ( 2s)] 90 ≤ f2≤ 146 (95.5% CL) |P/T| =0.3 DAFNE04 Frascati June 7, 2004

  23. sin2f2 : buud,B0p+p- DAFNE04 Frascati June 7, 2004

  24. f3measurement, B-D(*)0K- DAFNE04 Frascati June 7, 2004

  25. Doubly Cabibbo suppressed K* ρ-ω interference f3measurement, B-D(*)0K- Construct f as sum of known two-body resonances plus non-resonant term, fit to continuum D*-to-D-to-Kππ data. DAFNE04 Frascati June 7, 2004

  26. L = 140 fb-1 73 events 73 events f3measurement, B-D(*)0K- DAFNE04 Frascati June 7, 2004

  27. B+ D(*)0K+fit result B+ D0K+ B+ D*0K+ r+=0.29±0.19, θ+=353±38° r- =0.38±0.19, θ- =249±32° r+=0.40±0.15, θ+=256±19° r- =0.21±0.15, θ- = 71±37° DAFNE04 Frascati June 7, 2004

  28. Combined fit: f3measurement, B-D(*)0K- DAFNE04 Frascati June 7, 2004

  29. Belle and BaBar continue to refine their measurements of from ccs modes. _ Conclusion Both experiments are using their high-luminosity data samples to probe for new physics in rare B decays: over-constrain the sides and angles of the Unitarity Triangle.   140fb-1 270fb-1 >500fb-1 today this summer in two years? ? DAFNE04 Frascati June 7, 2004

  30. Conclusion Many new/updated results utilizing ~230–280 fb-1 of data per experiment will be shown this summer. Watch this space! DAFNE04 Frascati June 7, 2004

  31. CP eigenstates (xf CP eigenvalue) DAFNE04 Frascati June 7, 2004

  32. Continuous Injection DAFNE04 Frascati June 7, 2004

  33. z= +1 for B0 tag 1 for B0 tag sin2f2 : buud Time-dependent CP asymmetries in B0 π+π– -- the best way to access the CKM angle f2 z z Dt=Dz/(bgc) direct CP asymmetry DAFNE04 Frascati June 7, 2004

  34. sin2f2 : buud,B0r+r- DAFNE04 Frascati June 7, 2004

  35. L = 113 fb-1 sin2f2 : buud,B0r+r- DAFNE04 Frascati June 7, 2004

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