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b -Production papers

b -Production papers. PRL 74 (1995) (  b result superseded by PL B487) PL B370 (1996) PL B487 (2000) PRL 84 (2000) PRL 85 (2000) * Authors include 2xUvA, 2xKUN 9 CDF papers 4 UA1 papers 7 Theory papers 7 D0 notes Links/titles on NIKHEF@D0 homepage (analysis topics – impTag pages).

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b -Production papers

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  1. b-Production papers • PRL 74 (1995) (b result superseded by PL B487) • PL B370 (1996) • PL B487 (2000) • PRL 84 (2000) • PRL 85 (2000) * Authors include 2xUvA, 2xKUN • 9 CDF papers • 4 UA1 papers • 7 Theory papers • 7 D0 notes Links/titles on NIKHEF@D0 homepage (analysis topics – impTag pages) 1

  2. Phys.Lett.B487 (2000) • “The bbbar Production Cross Section and Angular Correlations in ppbar Collisions at s = 1.8 TeV” • Trigger: 1 muon, 1 jet (6.5 pb-1 from ’92-’93) • Inclusive b-quark cross sections • Dimuon sample, both jets b-tagged (pTrel, fraction of longitudinal momentum rz, time of passage t0) •  b(pTb>pTmin) for pTmin = 8 – 25 GeV/c • Repeated measurement of PRL 74 (1995): same sample, single muons •  b(pTb>pTmin) for pTmin = 6 – 15 GeV/c • Measurement of dbb/d 2

  3. Phys.Rev.Lett. 84 (2000) • “Small-Angle Muon and Bottom-Quark Production in ppbar Collisions at s = 1.8 TeV” • Data from low luminosity ’94-’95 run (104nb-1) • 2.4<|y|<3.2, trigger: 1 SAMUS track (>3GeV) • Inclusive muon sample  d/dpTdy • b-quark fraction from pTrel •  b for rapidity 2.40-2.65 and 2.65-3.20 • Additional measurement on (+jet) data subset 3

  4. Phys.Rev.Lett.85 (2000) • “Cross Section for b-Jet Production in ppbar Collisions at s = 1.8 TeV” • b-Jets vs b-Quarks reduce model dependence when comparing to theory • 5.2pb-1 (1995 run), trigger: jet + muon • Inclusive muon sample, b-jet component extracted using pTrel • d/dETbJet for ET = ~27-95 GeV (limited by pTrel) • Extracted b-fraction is dominant source of uncertainty in  4

  5. General strategies • Inclusive single (di-) muon sample, inclusive (di-) muon cross section, extract b-quark cross section using pTrel (D0: PLB487, PRL84, PRL74) or using “given” fraction fb (D0 note 3632, CDF: PRL71,2396) • Inclusive muons + jets, b-jet cross section using pTrel (D0: PRL 85, D0 note 3703, D0 note 3705 (quarks), D0 note 3734) • Inclusive J/ sample, inclusive b-quark cross section using muon transverse impact parameter (D0: PLB370) or mass + secondary vertex (CDF: PRL75) • Muon + jet, second jet with displaced vertex (CDF: PRD61) • Inclusive electron production, extract b-quark cross section using charge correlations and pTrel (CDF: PRL71,500) • Exclusive BJ/K, J/  (CDF: PRL68) 5

  6. Inclusive (di-) muons • Muon trigger • dsm/dx = (1/LDx)x(N f/e) • X = pTm, ym • N = number of tagged (fitted) muons • f = muon momentum unsmearing factor • e = detection efficiency • sb(pT>pTmin)= dsm/dpT fb  a  … • fb = b fraction, based onpTrel, likelihood fit, MC • a = pT>pTmin correction factor (from MC) 6

  7. Inclusive J/ • Trigger: 2 muons • J/ inclusive cross section using Mmm, Im, pTrelmm • fb from opposite sign dimuon impact parameter and mass (D0, 1996) or reconstructed secondary vertex ct and mass (CDF, 1995) 7

  8. Inclusive muons + jets • Trigger: muon + jet • dsb/dET = (Ufb / 2BLDxeA)x(DN/DET) • U(ET) = jet energy resolution smearing • fb(ET) = b-fraction using pTrel • B = branching fraction for bm+X • A = muon tagging acceptance correction • e = muon + jet detection efficiency • Fb is dominant source of error on cross section 8

  9. Dominating uncertainties • b-fraction (tagging / MC) 9%-39% • Integrated Luminosity 5%-10% • Trigger efficiency 3%-19% • Offline selection efficiency 4%-6% • Jet ET scale 15%-8% • Jet ET resolution 7%-3% • Tagging acceptance 9%-12% • Muon momentum resolution 6%-41% • Other background subtraction ~15% 9

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