Measurement of the b jet cross section in events with a Z boson in pp¯ collisions at s=1.96TeV (original) (raw)

A measurement of the inclusive bottom jet cross section is presented for events containing a Z boson in pp collisions at √ s = 1.96 TeV using the Collider Detector at Fermilab. Z bosons are identified in their electron and muon decay modes, and b jets with E T > 20 GeV and |η| < 1.5 are identified by reconstructing a secondary decay vertex. The measurement is based on an integrated luminosity of about 330 pb −1 . A cross section times branching ratio of σ(Z + b jets) × B(Z → ℓ + ℓ − ) = 0.93 ± 0.36 pb is found, where B(Z → ℓ + ℓ − ) is the branching ratio of the Z boson or γ * into a single flavor dilepton pair (e or µ) in the mass range between 66 and 116 GeV/c 2 . The ratio of b jets to the total number of jets of any flavor in the Z sample, within the same kinematic range as the b jets, is 2.36 ± 0.92%. Here, the uncertainties are the quadratic sum of statistical and systematic uncertainties. Predictions made with NLO QCD agree, within experimental and theoretical uncertainties, with these measurements. 7