Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV

We report the results of a study of color coherence effects in ppbar collisions based on data collected by the D0 detector during the 1994-1995 run of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8 TeV. Initial-to-final state color interference effects are studied by examining particle distribution patterns in events with a W boson and at least one jet. The data are compared to Monte Carlo simulations with different color coherence implementations and to an analytic modified-leading-logarithm perturbative calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters

The bb ¯ ¯ bb¯ production cross section and angular correlations in pp ¯ ¯ ¯ pp¯ collisions at s √ s = 1.8 TeV

We present measurements of the bb-bar Image production cross section and angular correlations using the DØ detector at the Fermilab Tevatron pp-bar Collider operating at ?s = 1.8 TeV. The b quark production cross section for |y^b| < 1.0 and pT^b > 6 GeV/c is extracted from single muon and dimuon data samples. The results agree in shape with the next-to-leading order QCD calculation of heavy flavor production but are greater than the central values of these predictions. The angular correlations between b and bbar quarks, measured from the azimuthal opening angle between their decay muons, also agree in shape with the next-to-leading order QCD prediction

The inclusive jet cross section in p-bar p collisions at ?s = 1.8 TeV using the kT algorithm.

The central inclusive jet cross section has been measured using a successive-combination algorithm for reconstruction of jets. The measurement uses 87.3 pb−1 of data collected with the DØ detector at the Fermilab Tevatron Collider during 1994–1995. The cross section, reported as a function of transverse momentum (pT>60 GeV) in the central region of pseudorapidity (|η|<0.5), exhibits reasonable agreement with next-to-leading order QCD predictions, except at low pT where the agreement is marginal