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B States at the Tevatron

B States at the Tevatron. Matthew Jones Purdue University / CDF. The Goals of Heavy Flavor Physics. Is the CKM matrix unitary ? Is it the source of CP violation seen in the Kaon system?. circa 1996. hep-ph/9612327. New. The Goals of Heavy Flavor Physics. New Physics:

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B States at the Tevatron

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  1. B States at the Tevatron Matthew Jones Purdue University/CDF Les Rencontres de Physique de la Vallee d'Aoste, 2008

  2. The Goals of Heavy Flavor Physics Is the CKM matrix unitary? Is it the source of CP violation seen in the Kaon system? circa 1996 hep-ph/9612327 La Thuile, 2008

  3. New The Goals of Heavy Flavor Physics • New Physics: • Expect many new phases in quark couplings • Should be manifest at some level in heavy flavor decays • Could be used to probe details of flavor structure in new physics scenarios • Will require determining heavy flavor matrix elements with great precision Lattice QCD HQET (and kin) La Thuile, 2008

  4. Heavy Quark Expansions: Mass splittings hep-lat/0510113 Physical light quark masses Physical heavy quark masses Lattice QCD HQET ChPT (small lattice spacing) (large lattice volume) NRQCD Symanzik-improved staggered quarks Gold plated processes for Lattice QCD: Absolute mass How reliable are these methods? How can we check? Talk by Vittorio Lubicz this afternoon! La Thuile, 2008

  5. 0 B s A CP • Orbitally excited B mesons • New B-flavored baryons • Λb lifetime • Bc mass and lifetime Talk by Heriberto Castilla this afternoon! La Thuile, 2008

  6. 45 MeV photon (unreconstructed) P-Wave B Mesons eg, Godfrey & Isgur, Phys. Rev. D32, 132 (1985). Also, Falk and Mehen, Phys. Rev. D53, 231 (1996). La Thuile, 2008

  7. Using B+ J/ψK+, D0π, D03π: overlaps with direct P-Wave B Mesons Using B+ J/ψK+: Published PRL 99, 172001 (2007) La Thuile, 2008

  8. 95±23 36±9 125±25 B*s2B+K- decays (25±10) hep-ex/0711.0319, Accepted by PRL hep-ex/0710.4199, Accepted by PRL P-Wave B0s Mesons Kaon ID: dE/dx + Time-of-Flight La Thuile, 2008

  9. P-Wave B Mesons Properties: Production Rates from DØ: La Thuile, 2008

  10. B-flavored Baryons Isospin Strangeness Spin 1/2 ground state Using fully reconstructed Λb decays Excited spin 3/2 state Using clean J/ψ signal ??? La Thuile, 2008

  11. Observation of Σb at CDF • Analysis optimization • Discriminating variables for • pT(Σb) • Pion impact parameter • Angular information in decay 3180±60 ΛbΛ+cπ- decays in 1 fb-1 Signal from Monte Carlo Background from Q sidebands, away from expected signal region. La Thuile, 2008

  12. Signal region chosen based on theoretical expectations (HQET): Dominant background from Λbwith a random track. Observation of Σb at CDF La Thuile, 2008

  13. Within 2 MeV of predicted splitting... Observation of Σb at CDF arXiv:hep-ph/0307243 arXiv:hep-ph/0611306 Published PRL 99, 202001 (2007) La Thuile, 2008

  14. Challenge: low pT, displaced track from Observation of DØ: dedicated track reconstruction algorithm CDF: dedicated tracking of Ξ- in silicon detector La Thuile, 2008

  15. Ξb Observation CDF II, Published: PRL 99, 052002 (2007) • Prediction based on same technique as Σb-Λb prediction: Published: PRL 99, 052001 (2007) (arXiv:0706.2163) • Clean enough to consider lifetime measurements? La Thuile, 2008

  16. Theory Experiment, ΛbΛc+ℓ-X B-baryon Lifetimes Reaching agreement? La Thuile, 2008

  17. Theory Experiment, ΛbJ/ψΛ New Measurements Most precise measurements to date Maybe... maybe not... La Thuile, 2008

  18. 171±20 Λb decays 717±38 B0J/ψ K0s Consistent with PDG average. DØ Analysis of ΛbJ/ψΛ (using world average B0 lifetime) Published: Phys. Rev. Lett. 99, 142001 (2007). La Thuile, 2008

  19. 3.2σ higher than world average CDF Analysis of ΛbJ/ψΛ 538±38 (using world average B0 lifetime) hep-ex/0609021 - Accepted by PRL La Thuile, 2008

  20. Lifetimes in other decay modes consistent with world averages No evidence for bias from decay topology Some, but not all, systematic effects may be correlated with result from DØ. CDF and DØ lifetimes differ by only 1.7σ... CDF Analysis of ΛbJ/ψΛ Precise, independent measurements are needed! La Thuile, 2008

  21. Blind search, optimized using B+J/ψK+ as proxy for B-c decay. Precise mass measurement: Lattice prediction: CDF: Exclusive decay CDF II 2.4 fb-1 108±15 candidates more than 8σ hep-ex/0712.1506 – submitted to PRL hep-lat/0411027 La Thuile, 2008

  22. DØ Observation of Preliminary: February 22, 2008 DØ 1.3 fb-1 54 ±12 events Now using 3D impact parameter significance: Blind search using B+J/ψK+ as proxy for Bc Corrected for observed mass biases, consistent with CDF result. La Thuile, 2008

  23. Reconstruct J/ψμ+μ-, add a third track Apply muon ID, pT and vertexing requirements Evidence for semi-leptonic Bc decays (includes ) DØ: Bc Lifetime La Thuile, 2008

  24. Backgrounds constrained by M(J/ψμ) Prediction from QCD sum rules: DØ: Bc Lifetime hep-ph/0308214 • Consistent with previous measurements. • Most precise measurement to date. La Thuile, 2008

  25. Summary from CDF and DØ • New B states observed over the past year: • No surprises: all were expected to exist • Demonstrates the power of a hadron collider for heavy flavor physics • B hadron lifetimes: • Continue to be quite interesting! • Lifetimes of newly observed baryons? • Bc increasingly well characterized • Useful constraints? La Thuile, 2008

  26. Backup Material La Thuile, 2008

  27. 8x12 layer drift chamber, |η|<1 Muon coverage |η|<1 Triggers: 20 kHz Level 1 rate Di-muon, pT>1.5 GeV Displaced tracks 8x2 layer fiber tracker, |η|<2 Muon coverage |η|<2 Triggers: 2 kHz Level 1 rate Single muon, pT> 3 GeV Di-muon, pT > 2 GeV The Experiments La Thuile, 2008

  28. Exclusive B Decays 23,300 B+ J/ K+ from 1.3 fb-1 51,500 B+ J/ K+ from 1.5 fb-1 (18,000 per fb-1) (34,000 per fb-1) σ~ 40 MeV/c2 σ~ 10 MeV/c2 ... but superb rapidity coverage! La Thuile, 2008

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