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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

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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!

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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

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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

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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

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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

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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:

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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

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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

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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…

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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

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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:

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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)

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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

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

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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

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J. Pursley, Beauty 0617 Backup Slides

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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

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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

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J. Pursley, Beauty 0620 b Two Peak Fit

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