168 research outputs found
Energy Calibration of b-Quark Jets with Z->b-bbar Decays at the Tevatron Collider
The energy measurement of jets produced by b-quarks at hadron colliders
suffers from biases due to the peculiarities of the hadronization and decay of
the originating B hadron. The impact of these effects can be estimated by
reconstructing the mass of Z boson decays into pairs of b-quark jets. From a
sample of 584 pb-1 of data collected by the CDF experiment in 1.96 TeV
proton-antiproton collisions at the Tevatron collider, we show how the Z signal
can be identified and measured. Using the reconstructed mass of Z candidates we
determine a jet energy scale factor for b-quark jets with a precision better
than 2%. This measurement allows a reduction of one of the dominant source of
uncertainty in analyses based on high transverse momentum b-quark jets. We also
determine, as a cross-check of our analysis, the Z boson cross section in
hadronic collisions using the b-bbar final state as sigma x B(Z->b-bbar) = 1578
+636 -410 pb.Comment: 35 pages, 9 figures, submitted to Nuclear Instruments and Methods in
Physics Research Section
Proton-Antiproton Collider Physics
Summary of the 10th Topical Workshop on Proton-Antiproton Collider Physics,
Fermilab, May 9-13, 1995.Comment: Summary of the 10th Topical Workshop on Proton-Antiproton Collider
Physics, Fermilab, May 9-13, 1995. Postscript file (34 pages with 82 embedded
figures; 5.7 MB) available at
http://www-cdf.fnal.gov/physics/conf95/cdf3225_pbarp_wkshp_summary.p
Measurement of charged-particle multiplicities in gluon and quark jets in p(p)over-bar collisions at root s=1.8 TeV
We report the first largely model independent measurement of charged particle multiplicities in quark and gluon jets, N-q and N-g, produced at the Fermilab Tevatron in p (p) over bar collisions with a center-of-mass energy of 1.8 TeV and recorded by the Collider Detector at Fermilab. The measurements are made for jets with average energies of 41 and 53 GeV by counting charged particle tracks in cones with opening angles of θ(c)=0.28, 0.36, and 0.47 rad around the jet axis. The corresponding jet hardness Q=E-jetθ(c) varies in the range from 12 to 25 GeV. At Q=19.2 GeV, the ratio of multiplicities r=N-g/N-q is found to be 1.64± 0.17, where statistical and systematic uncertainties are added in quadrature. The results are in agreement with resummed perturbative QCD calculations
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