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February 28, 2008Les Rencontres de Physique de la Vallee d'Aoste, 2008 1 B States at the Tevatron Matthew Jones Purdue UniversityPurdue University/CDFCDF.

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Presentation on theme: "February 28, 2008Les Rencontres de Physique de la Vallee d'Aoste, 2008 1 B States at the Tevatron Matthew Jones Purdue UniversityPurdue University/CDFCDF."— Presentation transcript:

1 February 28, 2008Les Rencontres de Physique de la Vallee d'Aoste, 2008 1 B States at the Tevatron Matthew Jones Purdue UniversityPurdue University/CDFCDF

2 February 28, 2008La Thuile, 20082 The Goals of Heavy Flavor Physics hep-ph/9612327 circa 1996 Is the CKM matrix unitary? Is it the source of CP violation seen in the Kaon system?

3 February 28, 2008La Thuile, 20083 The Goals of Heavy Flavor Physics New 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)

4 February 28, 2008La Thuile, 20084 hep-lat/0510113 Lattice QCD Physical light quark masses Physical heavy quark masses HQET ChPT (small lattice spacing) (large lattice volume) Symanzik-improved staggered quarks NRQCD Gold plated processes for Lattice QCD: Absolute mass Heavy Quark Expansions: Mass splittings How reliable are these methods? How can we check? Talk by Vittorio Lubicz this afternoon!

5 February 28, 2008La Thuile, 20085 Orbitally excited B mesons New B-flavored baryons Λ b lifetime B c mass and lifetime Talk by Heriberto Castilla this afternoon!

6 February 28, 2008La Thuile, 20086 P-Wave B Mesons 45 MeV photon (unreconstructed) eg, Godfrey & Isgur, Phys. Rev. D32, 132 (1985). Also, Falk and Mehen, Phys. Rev. D53, 231 (1996).

7 February 28, 2008La Thuile, 20087 P-Wave B Mesons Published PRL 99, 172001 (2007) Using B +  J/ ψ K +, D 0 π, D 0 3 π: Using B +  J/ ψ K + : overlaps with direct

8 February 28, 2008La Thuile, 20088 P-Wave B 0 s Mesons 36 ±9 95 ±23 hep-ex/0710.4199, Accepted by PRL Kaon ID: dE/dx + Time-of-Flight hep-ex/0711.0319, Accepted by PRL 125 ±25 B * s2  B + K - decays (25 ±10)

9 February 28, 2008La Thuile, 20089 P-Wave B Mesons Properties: Production Rates from D Ø:

10 February 28, 2008La Thuile, 200810 B-flavored Baryons Strangeness Isospin Excited spin 3/2 state Spin 1/2 ground state Using fully reconstructed Λ b decays Using clean J/ ψ signal ???

11 February 28, 2008La Thuile, 200811 Analysis optimization 3180 ±60 Λ b  Λ + c π - decays in 1 fb -1 Observation of Σ b at CDF Background from Q sidebands, away from expected signal region. Discriminating variables for p T ( Σ b ) Pion impact parameter Angular information in decay Signal from Monte Carlo

12 February 28, 2008La Thuile, 200812 Observation of Σ b at CDF Signal region chosen based on theoretical expectations (HQET): Dominant background from Λ b with a random track.

13 February 28, 2008La Thuile, 200813 Within 2 MeV of predicted splitting... Observation of Σ b at CDF arXiv:hep-ph/0307243 arXiv:hep-ph/0611306 Published PRL 99, 202001 (2007)

14 February 28, 2008La Thuile, 200814 CDF: dedicated tracking of Ξ - in silicon detector Observation of Challenge: low p T, displaced track from D Ø : dedicated track reconstruction algorithm

15 February 28, 2008La Thuile, 200815 Prediction based on same technique as Σ b -Λ b prediction: Ξ b Observation (arXiv:0706.2163) Published: PRL 99, 052002 (2007) Published: PRL 99, 052001 (2007) CDF II, Clean enough to consider lifetime measurements?

16 February 28, 2008La Thuile, 200816 B-baryon Lifetimes Theory Experiment, Λ b  Λ c + ℓ - X 1.00 0.97 0.94 0.90 0.86 OPAL, 96 CDF, 96 ALEPH, 98 DELPHI, 99 D Ø, 2007 Reaching agreement?

17 February 28, 2008La Thuile, 200817 New Measurements Theory Experiment, Λ b  J/ψΛ 1.00 0.97 0.94 0.90 0.86 Maybe... maybe not... D Ø, 2007 CDF, 2007 Most precise measurements to date

18 February 28, 2008La Thuile, 200818 D Ø Analysis of Λ b  J/ψΛ 171 ± 20 Λ b decays 717±38 B 0  J/ψ K 0 s Published: Phys. Rev. Lett. 99, 142001 (2007). Consistent with PDG average. (using world average B 0 lifetime)

19 February 28, 2008La Thuile, 200819 CDF Analysis of Λ b  J/ψΛ 3.2 σ higher than world average 538 ±38 hep-ex/0609021 - Accepted by PRL (using world average B 0 lifetime)

20 February 28, 2008La Thuile, 200820 CDF Analysis of Λ b  J/ψΛ 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 D Ø. CDF and DØ lifetimes differ by only 1.7σ... Precise, independent measurements are needed!

21 February 28, 2008La Thuile, 200821 CDF: Exclusive decay Blind search, optimized using B +  J/ ψ K + as proxy for B - c decay. Precise mass measurement: Lattice prediction: hep-lat/0411027 CDF II 2.4 fb -1 hep-ex/0712.1506 – submitted to PRL 108 ±15 candidates more than 8σ

22 February 28, 2008La Thuile, 200822 D Ø Observation of D Ø 1.3 fb -1 Now using 3D impact parameter significance: Blind search using B +  J/ ψ K + as proxy for B c Corrected for observed mass biases, consistent with CDF result. 54 ±12 events Preliminary: February 22, 2008

23 February 28, 2008La Thuile, 200823 Reconstruct J/ ψ  μ + μ -, add a third track Apply muon ID, p T and vertexing requirements Evidence for semi-leptonic B c decays D Ø: B c Lifetime (includes )

24 February 28, 2008La Thuile, 200824 D Ø: B c Lifetime Backgrounds constrained by M(J/ ψμ) Prediction from QCD sum rules: Consistent with previous measurements. Most precise measurement to date. hep-ph/0308214

25 February 28, 2008La Thuile, 200825 Summary from CDF and D Ø 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? B c increasingly well characterized Useful constraints?

26 February 28, 2008La Thuile, 200826

27 February 28, 2008La Thuile, 200827 The Experiments 8x12 layer drift chamber, | η|<1 Muon coverage |η|<1 Triggers: 20 kHz Level 1 rate –Di-muon, p T >1.5 GeV –Displaced tracks 8x2 layer fiber tracker, | η|<2 Muon coverage |η|<2 Triggers: 2 kHz Level 1 rate –Single muon, p T > 3 GeV –Di-muon, p T > 2 GeV

28 February 28, 2008La Thuile, 200828 Exclusive B Decays 51,500 B +  J/  K + from 1.5 fb -1 (34,000 per fb -1 ) 23,300 B +  J/  K + from 1.3 fb -1 (18,000 per fb -1 ) σ  ~ 10 MeV/c 2 σ  ~ 40 MeV/c 2... but superb rapidity coverage!


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