1. Heavy Flavor Production at the Tevatron Jennifer Pursley The Johns Hopkins University on behalf of the CDF and D0 Collaborations Beauty 2006 - University of Oxford, UK September 25-29, 2006

2. J. Pursley, Beauty 062 BRAND NEW RESULT!  b (*)± search B hadron relative fragmentation fractions B + cross section using B + → J/  K + (1S) production cross section  b → J/   J/ search and production upper limit Focus of this talk See many other CDF and D0 talks for more interesting b and c results from the Tevatron!

3. J. Pursley, Beauty 063 Triggers and Data Samples Analyses use between 160 pb -1 and 1.1 fb -1 of data Trigger paths used by these analyses:  Di-Muon (J/  ) [CDF + D0]  Displaced track + lepton (e,  ) [CDF]  2 track trigger [CDF] Skipping all detector and Tevatron review! D0

4. J. Pursley, Beauty 064  b Motivation  b only established B baryon Enough statistics at Tevatron to probe other heavy baryons Next accessible baryons:  b : b{qq}, q = u,d; J P = S Q + s qq = 3/2 + ( b * ) = 1/2 + ( b ) HQET extensively tested for Qq systems; interesting to check predictions for Qqq systems Baryon spectroscopy also tests Lattice QCD and potential quark models

5. J. Pursley, Beauty 065 Reconstructing  b With 1.1 fb -1, world’s largest sample of  b : ~3000 Use 2 track trigger to reconstruct:  b decays at primary vertex Combine  b with a prompt track to make a  b candidate  b Mass Plot

6. J. Pursley, Beauty 066  b Search Methodology Separate  b - and  b + :  (+ c.c.) Search for resonances in mass difference: Q = m( b ) - m( b ) – m   Use reconstructed  b mass → remove  b mass systematic error Unbiased optimization  Optimize  b cuts with  b signal region blinded: 30 < Q < 100 MeV/c 2  b backgrounds:   b Hadronization + Underlying Event – Dominant!  B meson Hadronization  Combinatorial Bkg Fix background contributions from data or PYTHIA Monte Carlo

7. J. Pursley, Beauty 067  b Observation Observe signals consistent with lowest lying charged  b states With unbinned likelihood fit, measure events And mass difference values:

8. J. Pursley, Beauty 068 b Fragmentation Fractions Measure flavor dependence of fragmentation process for b quarks (non-perturbative) Reconstruct semi-leptonic decays of B 0, B -, B s 0, and  b 0 in 360 pb -1 of data  ℓ – D 0, ℓ – D +, ℓ – D *+, ℓ – D s +, ℓ –  c +  Use Particle ID likelihood cuts (important for  c + signal) Determine sample comp. from charm hadron BRs Indirect semi-lep decays and excited B hadrons explicitly included

9. J. Pursley, Beauty 069 Fragmentation Fraction Results f u, f d, f s, f  = probability to result in B -, B 0, B s 0,  b 0 Use B hadron transverse momentum (p T ) threshold of 7 GeV/c Agrees with world average of fragmentation fraction of B - relative to B 0 f b differs from LEP by ~2.2

10. J. Pursley, Beauty 0610 B + Production Cross Section 8197 ± 239 B ± mesons total Divide in 5 bins of p T and measure differential cross section as a function of p T, in units of nb/GeV/c Integrated cross section for p T ≥ 25 GeV/c = 21.7 ± 3.7 nb Using 740 pb -1 of data, reconstruct B + → J/  K + To be submitted to PRD very soon…

11. J. Pursley, Beauty 0611 Total B + Production Cross Section Combined stat & syst errors Agrees with previous Tevatron measurements  1.8 TeV cross section increased by 10% Also within the range of FONLL theoretical predictions with  f u = 0.389  CTEQ6M fits to parton distribution functions

12. J. Pursley, Beauty 0612 (1S) Production With 160 pb -1, reconstruct (1S) →  +  - Unresolved (2S) and (3S) signals Previous studies at CDF limited to at √s = 1.8 TeV Divide into three rapidity regions: 

13. J. Pursley, Beauty 0613 (1S) Diff. Cross Section Little variation between rapidity regions Also consistent with previous CDF measurement Allows a more precise determination of parameters of bottomonium production models Phys. Rev. Lett. {94}, 232001 (2005)

14. J. Pursley, Beauty 0614 Search for  b → J/ J/ Spin-singlet bb bound state  b yet to be observed (pp →  b X) ~  b at Tevatron energy scale Look for  b decay into J/  J/  in 1.1 fb -1  Large uncertainty in expected BR  Expect between 0.2 and 20 events with both J/ decaying to  +  -  Reconstruct as 3 + track

15. J. Pursley, Beauty 0615  b → J/ J/ Results Expected 3.6 bkg events; observe 3 events Set upper limit for production cross section:

16. J. Pursley, Beauty 0616 First observation of lowest lying charged  b states!  With m( b ) = 5619.7 ± 1.2 (stat) ± 1.2 (syst) MeV/c 2, Precision measurements of b production properties  b fragmentation fractions  (1S) and B + production cross sections  Upper limit on  b → J/  J/  production More results on the way… Summary

17. J. Pursley, Beauty 0617 Backup Slides

18. J. Pursley, Beauty 0618  b Systematics ParameterTracking  b Sample Comp.  b Ha+UE Norm.  b Ha+UE Shape  b Ha+UE Reweight Det. Reso.  b Nat. Width Total  b - Q (Mev/c 2 ) 0.06 -0.06 0.00 -0.03 0.009 -0.002 0.000 -0.011 0.04 -0.0004 0.0 -0.011 0.009 -0.005 0.07 -0.07  b + Q (Mev/c 2 ) 0.06 -0.06 0.03 0.0 0.013 -0.013 0.013 0.0 -0.11 0.0 -0.014 0.01 -0.02 0.07 -0.13  b * -  b Q (Mev/c 2 ) 0.06 -0.06 0.05 0.0 0.14 -0.13 0.04 0.0 0.32 0.0 0.02 0.0 0.07 -0.07 0.37 -0.16  b - events 0.0 0.7 0.0 2.2 -2.2 0.3 0.0 7.4 0.0 0.3 0.0 3.4 -3.4 8.5 -4.0  b + events 0.0 3.3 0.0 2.1 -2.1 1.2 0.0 2.3 -1.8 0.3 0.0 1.8 -2.0 5.0 -3.4  b *- events 0.0 0.4 0.0 4.8 -4.7 0.3 0.0 14.7 0.0 0.1 0.0 1.7 -1.7 15.6 -5.0  b *+ events 0.0 7.3 0.0 4.8 -4.8 2.8 0.0 4.6 -2.9 0.2 0.0 0.8 -0.8 10.3 -5.7

19. J. Pursley, Beauty 0619  b Fit Likelihood Ratios Hypothesis  (-ln £) 1/LR “NULL” vs. “4 Peak” 44.72.6e19 “2 Peak” vs. “4 Peak” 14.31.6e6 No  b - Peak 10.43.3e4 No  b + Peak 1.13 No  b *- Peak 10.12.4e4 No  b *+ Peak 9.81.8e4

20. J. Pursley, Beauty 0620  b Two Peak Fit