Inclusive jet production at 630 and 1800 GeV

Inclusive jet cross sections measured at the Fermilab Tevatron p{anti p} Collider are presented and compared to theoretical predictions. The cross sections are reported as a function of jet E{sub T} at beam energies of {radical}s = 0.63 TeV and {radical}s = 1.8 TeV. A recent preliminary result at {radical}s = 1.8 TeV by the CDF collaboration confirms an earlier published result which is in good agreement with Quantum Chromodynamics (QCD) below E{sub T} = 250 GeV, but which shows excess jet production above 250 GeV. A final result by the D0 collaboration is in good agreement with QCD at all E{sub T} . An uncertainty analysis, including a final D0 systematic error matrix, indicates the two measurements are consistent. Preliminary {radical}s = 0.63 TeV cross sections from the two experiments are consistent with one another but somewhat lower than QCD predictions. Likewise, preliminary measurements of the ratio of cross sections at {radical}s = 0.63 TeV and {radical}s = 1.8 TeV are experimentally consistent, but approximately 20% below predictions