First QCD results obtained from the CDF experiment using Run II data are reported. The Run II physics program at the Tevatron started in the spring of 2001, with protons and anti-protons colliding at an energy of (square root)s = 1.96 TeV. The size of the data sample already compares to that of Run I. Results presented here include the measurement of the inclusive jet cross section, a search for new particles decaying to dijets, and a study of diffractive dijet events.

We present results on the inclusive jet cross section at (square root)s = 1800 GeV and 630 GeV, the two-jet cross section, multijet physics and the multijet differential cross section from the CDF experiment at the Fermilab Tevatron Collider.

Abstract: Recent results of QCD studies from the CDF and D0 experiments at the Tevatron {bar p}p collider at Fermilab are presented. The inclusive jet cross section, the internal structure of jets, di-jet angular distributions, di-jet triple differential cross sections, and properties of multi-jet final states are studied and compared with NLO QCD predictions. The comparisons show good agreement between theoretical predictions and the experimental data in general. Some systematic disagreement between LO predictions and the data are observed in di-jet triple differential cross sections. Results of a rapidity gap study are also presented together with an upper limit on the gap fraction. In addition, the inclusive photon cross section and the di-photon cross sections are presented and compared with NLO QCD predictions.

Results are presented for hadronic jet and direct photon production at (square root){bar s} = 1800 GeV. The data are compared with next-to-leading QCD calculations. A new limit on the scale of possible composite structure of the quarks is also reported. 12 refs., 4 figs.

Experimental results on QCD measurements obtained in recent analyses and based on data collected with CDF Detector from the Run 1b Tevatron running cycle are presented. The scope of the talk includes major QCD topics: a measurement of the strong coupling constant[alpha][sub s], extracted from inclusive jet spectra and the underlying event energy contribution to a jet cone. Another experimental object of QCD interest, prompt photon production, is also discussed and the updated measurements by CDF of the inclusive photon cross section at 630 GeV and 1800 GeV, and the comparison with NLO QCD predictions is presented.