S. Behrends

Measurement of Dijet Angular Distributions by the Collider Detector at Fermilab.

We have used 106 pb^-1 of data collected in proton-antiproton collisions at sqrt(s)=1.8 TeV by the Collider Detector at Fermilab to measure jet angular distributions in events with two jets in the final state. The angular distributions agree with next to leading order (NLO) predictions of Quantum Chromodynamics (QCD) in all dijet invariant mass regions. The data exclude at 95% confidence level (CL) a model of quark substructure in which only up and down quarks are composite and the contact interaction scale is Lambda_ud(+)<1.6 TeV or Lambda_ud(-)<1.4 TeV. For a model in which all quarks are composite the excluded regions are Lambda(+)<1.8 TeV and Lambda(-)<1. 6 TeV.

Search for a Technicolor ωT Particle in Events with a Photon and a b-Quark Jet at Fermilab

If the technicolor {omega}{sub T} particle exists, a likely decay mode is {omega}{sub T}{r_arrow}{gamma}{pi}{sub T} , followed by {pi}{sub T}{r_arrow}b{bar b} , yielding the signature {gamma}b{bar b} . We have searched 85 pb{sup {minus}1} of data collected by the CDF experiment at the Fermilab Tevatron for events with a photon and two jets, where one of the jets must contain a secondary vertex implying the presence of a b quark. We find no excess of events above standard model expectations. We express the result as an exclusion region in the M{sub {omega}{sub T}}-M{sub {pi}{sub T}} mass plane. {copyright} {ital 1999} {ital The American Physical Society }