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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 La Thuile, 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. 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: At most one hadron in initial and final state. Particularly well suited for heavy hadron masses. La Thuile, 2008

  5. 0 B s A CP • Orbitally excited B mesons • New B-flavored baryons • Λb lifetime • Bc mass and lifetime 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: P-Wave B Mesons Using B+ J/ψK+: Published PRL 99, 172001 (2007) overlaps with direct 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 Published: PRL 99, 052002 (2007) • Prediction based on same technique as Σb-Λb prediction: • Clean enough to consider lifetime measurements? Published: PRL 99, 052001 (2007) (arXiv:0706.2163) 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 DØ Analysis of ΛbJ/ψΛ Consistent with PDG average. 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 La Thuile, 2008

  20. Lifetimes in many other decay modes consistent with world averages No evidence for bias due to decay topology Some, but not all, systematic effects may be correlated with result from DØ. CDF Analysis of ΛbJ/ψΛ • CDF and DØ results differ by only 2.3σ... • Precise, independent measurements would benefit both theory and experiment. 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 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 Significant evidence for semileptonic 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 possible, but challenging • Bc increasingly well characterized 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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