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B Physics at CDF

B Physics at CDF. Junji Naganoma University of Tsukuba. “New Developments of Flavor Physics“ Workshop 2009/03/09 @ Tennomaru, Aichi, Japan. B Physics at the Tevatron. Complements excellent programs at B-factories Pros Large production cross section: All bottom hadrons are produced

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B Physics at CDF

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  1. B Physics at CDF Junji Naganoma University of Tsukuba “New Developments of Flavor Physics“ Workshop 2009/03/09 @ Tennomaru, Aichi, Japan

  2. B Physics at the Tevatron • Complements excellent programs at B-factories • Pros • Large production cross section: • All bottom hadrons are produced • B+, B0, Bs, Bc+, b, … • Cons • Large combinatorics and messy events • Difficult to detect low pT  and 0’s from B decays • Inelastic cross section is a factor of 103 larger with roughly the same pT spectrum • Difficult to trigger on B’s Phys. Rev. D 71, 032001 (2005) Measured in inclusive J/ events  = 17.60.4(stat)+2.5-2.3 (syst.) b 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  3. B Physics Results Discussed Today • New results since last year’s workshop • Production: X(3872) • Lifetime: Bc, Bs, b • Rare Decay: Bs e+- • CP Violation: Bs J/ 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  4. X(3872) • First observed by Belle collaboration in 2003 • Confirmed by CDF, D0, and BaBar soon after • Observed in decay X(3872)J/+- • Nature of particle is still unknown • D*D “molecule”? 4-quark state? … • Precise mass measurement can provide clues • Observation of mass splitting offers evidence of tetra-quark state • Absolute mass checks possibility of a D*D bound-state 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  5. X(3872) Mass World best measurement • M(X) = 3871.61  0.16(stat)  0.19(syst) MeV/c2 • Result consistent with no mass splitting • Assign upper limit: m(X(3872)) < 3.6 MeV/c2 @ 95% C.L. 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  6. HFAG 2006 Interests in B Hadron Lifetimes • Test Heavy Quark Effective Theory (HQET) predictions • Have previously seen 1-2 discrepancies between lifetime predictions • and measurements in Bs and b • Expect (B+) > (B0)  (Bs) > (b) >> (Bc) • Shorter lifetimes indicate additional (non-SM) decay processes 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  7. Bs Lifetime Now Agrees with HQET • L=1.3 fb-1 • displaced vertex trigger • ~1100 fully reconstructed • Bs Ds-(-)+ • ~2000 partially reconstructed • BsDs-(0+): 0 not reconstructed • Sample composition by mass fit  K+ K- Ds- + Bs0 + World best measurement: consistent with theoretical prediction (Bs) = 1.518  0.041 (stat)  0.025 (syst) ps HQET prediction with (B0) ~ (Bs): (B0) = 1.530  0.009 ps 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  8. Bc+ Lifetime • L=1.0 fb-1 • di-muon trigger • Shorter lifetime than light B mesons • via weak decays of b or c quark • or via weak annihilation • Bc = b(~25%) + c(~65%) + W • Fit e, channel separately, then combined J/ + - Bc+ (e)+  consistent with theoretical prediction (Bc) = 0.475 +0.052-0.049 (stat)  0.025 (syst) ps Theory: (Bc) = 0.47  0.59 ps 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  9. b(bud) b Lifetime • 1.1 fb-1 • displaced vertex trigger • No helicity suppression • b  c+- decay • Sample composition from mass fit p K- c+ + b0 - World best measurement: consistent with prediction (b) = 1.410  0.046 (stat)  0.029 (syst) ps Theory: (b) = 1.346  0.077 ps 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  10. Rare Decays 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  11. Bs(d)  e+-, e+e- Search • Bs(d) e forbidden in SM • Possible with R-parity violating SUSY, ED, or Lepto-quarks • BR(B  ee) ~10-15 in SM Pati-Salam model allows for cross-generation couplings • Most of direct searches for LQ set limits in the order of • MLQ > 200-300 GeV/c2 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  12. Bs(d)e, ee Search Results Nbkg = 2.66  1.80 Nbkg = 0.94  0.63 Nbkg = 2.66  1.80 Nbkg = 0.81  0.63 95% C.L. limits: Br(Bsee) < 3.7  10-7 Br(Bdee) < 10.6  10-7 95% C.L. limits: Br(Bse) < 2.6  10-7, MLQ > 45 TeV/c2 Br(Bde) < 7.9  10-7, MLQ > 56 TeV/c2 All limits are world best 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  13. CP Violation 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  14. CP Violation in Bs J/ Decays • Analogously to the neutral B0 system, CP violation in Bs system occurs through • interference of decays with and without mixing: dominant contribution from top quark + • CP violation phase bs in SM is predicted to be • very small O(λ2) : =0.23 • → Any large CP phase is a clear sign of new physics ~ 2 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  15. Results in Flavor-Tagged Bs J/ • 1.5 discrepancy with SM at L=1.35 fb-1 • Updated results have 1.8 discrepancy with • SM s prediction. Assuming no CP violation (s=0) CP-odd CP-even mean lifetime: (Bs) = 1.53 ±0.04 (stat) ±0.01 (syst) ps = 0.02  0.05 (stat)  0.01 (syst) ps-1 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  16. CDF and D0 Combined Results • D0 result is very similar to CDF’s! (1.7 discrepancy with SM) • Updated CDF result is not included. G. Hou et al. suggest that discrepancy might due to t’ quark with mass ~300 GeV/c2 – 1 TeV/c2 (arXiv:0803.1234) t’ search in CDF = -2s arXiv:0808.1297 M(t’) > 311 GeV/c2 @ 95%C.L. 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  17. 8 fb-1 6 fb-1 current central value CDF only Probability of 5σ observation CDF+DØ (assume twice CDF) bs (radians) bs (radians) Prospects • Tevatron can search for large value of s, before LHC starts • 6/8 fb-1 expected at the end of 2009/2010 If s is indeed large, combined CDF and DØ results have good chance to prove it 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  18. Summary • CDF has a rich B-Physics program, complementary to B-factories. • Recent results (L<2.8 fb-1) include : • Lifetime measurements • Uncertainties are still dominated by statistics. • s measurent • 1.8 discrepancy with SM • Rare decay Bs  e searches Prospects • 5 fb-1 on tape and collecting ~50 pb-1/week • New s results expected this summer • Lifetime measurements with more than twice of data • New Bs results • And much more... • Higher precision measurements could give us a stronger hint • before the LHC turns on. 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

  19. Backup

  20. SUSY with R-parity violation D0-> mumu • SM Prediction:Br(D0)  410-13 • R-parity violating SUSY allows • enhancements up to 3.510-6 • L = 360 pb-1 • Branching ratio relative to D0+- • No excess observed World best limit Br(D0) < 5.3  10-7 @ 95% C.L. 21k22k < 9.8 10-4

  21. s Phase and the CKM Matrix - CKM matrix connects mass and weak quark eigenstates - Expand CKM matrix in λ = sin(Cabibbo) ≈ 0.23 ≈ • To conserve probability CKM matrix must be unitary • → Unitary relations can be represented as “unitarity triangles” • unitarity • relations: • unitarity • triangles: ~1 l2 ~ =1 very small CPV phase bs of order l2 accessible in Bs decays 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

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