Inclusive Jet Cross Sections in $\bar{p}p$ Collisions at $\sqrt{s}$= 630 and 1800 GeV

We have made a precise measurement of the inclusive jet cross section at $\sqrt{s}$=1800 GeV. The result is based on an integrated luminosity of 92 pb^{-1} collected at the Fermilab Tevatron $\bar{p}p$ Collider with the D\O detector. The measurement is reported as a function of jet transverse energy (60 GeV <= E_{T} < 550 GeV), and in the pseudorapidity intervals |\eta| <= 0.5 and 0.1 <= |\eta| <= 0.7. A preliminary measurement of the pseudorapidity dependence of inclusive jet production (|\eta| <= 1.5) is also discussed. The results are in good agreement with predictions from next-to-leading order (NLO) quantum chromodynamics (QCD). D\O has also determined the ratio of jet cross sections at $\sqrt{s}$=630 GeV and $\sqrt{s}$=1800 GeV (|\eta| <= 0.5). This preliminary measurement differs from NLO QCD predictions