Kinematics of t(t)over-bar events at CDF

The kinematic properties of t(t)over-bar events are studied in the W+ multijet channel using data collected with the CDF detector during the 1992-1995 runs at the Fermilab Tevatron collider corresponding to an integrated luminosity of 109 pb(-1). Distributions of a variety of kinematic variables chosen to be sensitive to different aspects of t (t) over bar production an compared with those expected from Monte Carlo calculations. A sample of 34 events rich in t(t)over-bar pairs is obtained by requiring at least one jet identified by the silicon vertex detector (SVX) as having a displaced vertex consistent with the decay of a b hadron. The data are found to be in good agreement with predictions of the leading order t(t)over-bar matrix element with color coherent parton shower evolution. [S0556-2821(99)04007-2].