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B Factory Results and Prospects

Workshop on the Interplay Between Collider and Flavo(u)r Physics. B Factory Results and Prospects. Outline: a few words on CKM b → s(g, g , l + l - ) b → d(g, g ) rare decays and D mixing. James D. Olsen Princeton University (on behalf of BaBar and Belle). CERN, December 3-4, 2007.

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B Factory Results and Prospects

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  1. Workshop on the Interplay Between Collider and Flavo(u)r Physics B Factory Results and Prospects • Outline: • a few words on CKM • b →s(g,g, l+l-) • b → d(g, g) • rare decays and D mixing James D. Olsen Princeton University(on behalf of BaBar and Belle) CERN, December 3-4, 2007

  2. Status of the B Factories Expected by summer 2008:L(Belle) = 1ab-1, L(BaBar) = 0.750ab-1 Most analyses use ~490fb-1(Belle) or ~350fb-1(BaBar), so expect effective doubling of total dataset by next summer Workshop on the Interplay Between Collider and Flavour Physics

  3. Impact of the B Factories and Tevatron 1998 2007 Enormous progress in the past decade has led to a paradigm change: Use precision CKM measurements to search for New Physics (NP) Workshop on the Interplay Between Collider and Flavour Physics

  4. Over-constraining CP Violation No Angles Angles only Errors dominated by statistics Errors dominated by systematics (thy+exp) Workshop on the Interplay Between Collider and Flavour Physics

  5. Status and Prospects for a B0→ (0 BaBar Preliminary @68%CL First time-dependent CPV measurment in B0→ r0r0: Final B Factory errors: sS ~ 0.50 Workshop on the Interplay Between Collider and Flavour Physics

  6. Measuring g Can also measure sin(2b+g) in tdcpv B0→ DX decays Combine all measurements! For illustration only CLEO-c can help! Workshop on the Interplay Between Collider and Flavour Physics

  7. Status and Prospects for g Belle data using B → DK, D*K, and D*K* with 357fb-1: 208fb-1 Depending on rB, can get tosstat ~ 8o – 14o with full dataset Workshop on the Interplay Between Collider and Flavour Physics

  8. Searching for New Physics in b → s: b → sg, b → sg, b → sl+l- Constraints from Bs mixing Workshop on the Interplay Between Collider and Flavour Physics

  9. CP Violation in b → sg +5 -5 -4 -3 -2 -1 0 +1 +2 +3 +4 Summer 2008 assuming same central value → Assuming no change in central values by summer 2008, still two modes with > 3s discrepancy Interpretation limited by hadronic uncertainties Workshop on the Interplay Between Collider and Flavour Physics

  10. BR and Acp in b →sg Analysis techniques: I) Fully inclusive (hadronic or leptonic tag) after subtraction II) semi-inclusive (sum of exclusive modes) L(fb-1) 9.1 5.8 140 81 81 • BF is systematics limited, fighting to < 5% difficult but not impossible Updated analyses from BaBar using > 300fb-1 are coming! • Acp (D0- too!) statistics limited (“forever”), should scale with lumi Workshop on the Interplay Between Collider and Flavour Physics

  11. CP Violation in B0→(KSp0)g SM spin-flip penalty: S  ms/mb*sin2b gL, gR interference! Ball and Zwicky Phys.Lett.B642:478-486,2006 • measurements statistics dominated (forever); expected final B Factory error ~0.17 • alternative analysis measuring photon helicity directly in B → Kppg possible, but VERY difficult Workshop on the Interplay Between Collider and Flavour Physics

  12. NP in FCNC: B → K(*)ll Historical example of interference and a new particle (Z0): Observation of Z0 in UA1(July 1983) g-Z0 interference in e+e- with s = 34.6GeV at DESY(June 1982) Modern opportunity in B→ K(*)l+l- : +? Workshop on the Interplay Between Collider and Flavour Physics

  13. Results and Prospects for BK(*)ll M. Nakao LP07 208fb-1 350fb-1 M. Nakao LP07 • BFs consistent with predictions • AFB inconsistent with C9/C10 sign flip • some “tension” (2s) with SM @ low-q2 B Factory dataset will triple in these modes by summer 2008(more data → more bins!) Workshop on the Interplay Between Collider and Flavour Physics

  14. Searching for New Physics in b → d: b → dg, b → dg Constraints from Bd mixing Workshop on the Interplay Between Collider and Flavour Physics

  15. CP Violation in B0 → K0K0 d Weak phases from mixing and decay cancel if top dominates: K0 s s Fleischer and Recksiegel, Eur.Phys.J.C38:251-259,2004 K0 SM Final error from the B Factories ~ 0.36 Workshop on the Interplay Between Collider and Flavour Physics

  16. CP Violation in B → rg Weak phase ~cancels plus spin-flip penalty (md/mb) → we really expect ~0! Ball, Jones, and Zwicky Phys.Rev.D75:054004,2007 Measured by Belle (600fb-1): Workshop on the Interplay Between Collider and Flavour Physics

  17. Vtd/Vts from b  (s,d) g Observation of B  rg by Belle and BaBar allows a complementary constraint on Vtd/Vts rg/K*g→ |Vtd/Vts| = 0.200 ± 0.021 (exp) ± 0.015 (thy)mixing → |Vtd/Vts| = 0.2060 ± 0.0007 (exp) ± 0.0081 (thy) Workshop on the Interplay Between Collider and Flavour Physics

  18. New Physics in Rare Decays Workshop on the Interplay Between Collider and Flavour Physics

  19. Searching for NP in B → tn Analysis techniques: • Difficult analysis: • leptonic or hadronic tag (low e) • at least two neutrinos • bkgs in Eextra difficult to model hadronic or leptonic tag Workshop on the Interplay Between Collider and Flavour Physics

  20. Results and Prospects for B → tn BaBar (350fb-1): (leptonic) (hadronic) (combined) Belle hadronic tag (414fb-1): M. Nakao LP07 World Average: Final B Factory error ~ 0.28, but could do better with new tracking improvements from BaBar and leptonic tag analysis from Belle Workshop on the Interplay Between Collider and Flavour Physics

  21. Observation of Not-Rare B → D(*)tn Accurate SM predictions: Sensitive to NP as in B → tn(small e,m masses could hide NP) C. Chen and C. Geng, hep-ph/0608166 A. Falk et al., PLB 326 145 (1994) B0→ D*+tn Workshop on the Interplay Between Collider and Flavour Physics

  22. NP Prospects in B → D(*)tn (485fb-1) (210fb-1) B → Dtn sensitivity to NP BaBar measurement Final B Factory error M. Tanaka hep-ph/9411405 Workshop on the Interplay Between Collider and Flavour Physics

  23. Lepton Flavor Violation in t decays Highly suppressed in SM! • Expected asymptotic limits: • t → mg < 2-3 x 10-8 • t → mmm < 2-3 x 10-8 (competitive with LHC @ 30fb-1) Workshop on the Interplay Between Collider and Flavour Physics

  24. Status of D0 Mixing Sensitivity to NP: BaBar 2007 ~5s • New @ Lepton-Photon 2007: • BaBar lifetime ratio (3.0s) • BaBar Dalitz Kpp0 (~2s) • CDF D → Kp analysis (3.2s) • still no sign of CP violation! CDF not yet included Workshop on the Interplay Between Collider and Flavour Physics

  25. Summary and Outlook • The last ~decade has seen enormous progress in the understanding of flavor physics • Precision measurements of CKM parameters have established KM as the dominant source CPV • Null searches for rare/forbidden decays has significantly reduced the phase space for NP • MFV is the most likely NP scenario • B Factories will end operations in 2008 • Total integrated luminosity ~ 1.7ab-1 • Approximately double the current dataset • Major effort to repeat measurements on the final datasets as soon as possible (major updates at ICHEP08) • “Interplay” will continue into the LHC era • Once NP is discovered at LHC, we’ll know exactly where to look for it at Belle and Babar • The far-future belongs to LHCb and SuperB! Workshop on the Interplay Between Collider and Flavour Physics

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