1. B States at the Tevatron
Matthew Jones
Purdue University/CDF
February 28, 2008
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/
February 28, 2008
La Thuile, 2008

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

4. hep-lat/
Physical light quark masses
Physical heavy quark masses
Lattice QCD
ChPT
HQET
(small lattice spacing)
(large lattice volume)
Symanzik-improved staggered quarks
NRQCD
Gold plated processes: At most one hadron in initial and final state.
Particularly well suited for heavy hadron masses.
February 28, 2008
La Thuile, 2008

5. A B Orbitally excited B mesons New B-flavored baryons Λb lifetimeCP B s
Orbitally excited B mesons
New B-flavored baryons
Λb lifetime
Bc mass and lifetime
February 28, 2008
La Thuile, 2008

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

7. P-Wave B Mesons overlaps with direct Using B+  J/ψK+, D0π, D03π:
Published PRL 99, (2007)
overlaps with direct
February 28, 2008
La Thuile, 2008

8. P-Wave B0s Mesons Kaon ID: dE/dx + Time-of-Flight 95±23 36±9
hep-ex/ , Accepted by PRL
hep-ex/ , Accepted by PRL
125±25 B*s2B+K- decays
(25±10)
February 28, 2008
La Thuile, 2008

9. Production Rates from DØ:
P-Wave B Mesons
Properties:
Production Rates from DØ:
February 28, 2008
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
???
February 28, 2008
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.
February 28, 2008
La Thuile, 2008

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

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

14. Observation of Challenge: low pT, displaced track from
CDF: dedicated tracking of Ξ- in silicon detector
DØ: dedicated track reconstruction algorithm
February 28, 2008
La Thuile, 2008

15. Ξb Observation Prediction based on same technique as Σb-Λb prediction:
Published: PRL 99, (2007)
Prediction based on same technique as Σb-Λb prediction:
Clean enough to consider lifetime measurements?
Published: PRL 99, (2007)
(arXiv: )
February 28, 2008
La Thuile, 2008

16. B-baryon Lifetimes 1.00 OPAL, 96 0.97 CDF, 96 0.94 ALEPH, 98 Theory
Experiment, ΛbΛc+ℓ-X
1.00
0.97
0.94
0.90
0.86
OPAL, 96
CDF, 96
ALEPH, 98
DELPHI, 99
DØ, 2007
Reaching agreement?
February 28, 2008
La Thuile, 2008

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

18. DØ Analysis of ΛbJ/ψΛ 171±20 Λb decays 717±38 B0J/ψ K0s
Consistent with PDG average.
Published: Phys. Rev. Lett. 99, (2007).
February 28, 2008
La Thuile, 2008

19. CDF Analysis of ΛbJ/ψΛ
538±38
3.2σ higher than world average
February 28, 2008
La Thuile, 2008

20. CDF Analysis of ΛbJ/ψΛ
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 and DØ results differ by only 2.3σ...
Precise, independent measurements would benefit both theory and experiment.
February 28, 2008
La Thuile, 2008

21. CDF: Exclusive decay
Blind search, optimized using B+J/ψK+ as proxy for B-c decay.
Precise mass measurement:
Lattice prediction:
hep-lat/
February 28, 2008
La Thuile, 2008

22. DØ Observation of DØ 1.3 fb-1 54 ±12 events
Preliminary: February 22, 2008
DØ 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.
February 28, 2008
La Thuile, 2008

23. DØ: Bc Lifetime Reconstruct J/ψμ+μ-, add a third track
(includes )
Reconstruct J/ψμ+μ-, add a third track
Apply muon ID, pT and vertexing requirements
Significant evidence for semileptonic Bc decays
February 28, 2008
La Thuile, 2008

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

26. Backup Material
February 28, 2008
La Thuile, 2008

27. The Experiments 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
February 28, 2008
La Thuile, 2008

28. ... but superb rapidity coverage!
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!
February 28, 2008
La Thuile, 2008