The Dijet Mass Cross Section at the Tevatron

At a center of mass energy of 1:8 TeV, high transverse energy jet production from hadron beams probes the smallscale structure of the proton down to 10 4 fm. Measurements of the dijet mass spectrum and angular distributions can be used to check consistency with QCD, constrain parton distribution functions, or constrain new physics such as quark compositeness. A previous analysis of the inclusive jet cross section by the CDF collaboration [1] reported an excess of jet production at high ET , while the corresponding analysis by the D0 collaboration [2] reported no such excess. The dijet mass measurements complement the inclusive jet cross-section measurements because both of the leading jets are included, and the angle between the jets is a part of the mass equation. This talk shows new results from CDF, and recent results from D0 on the dijet mass spectrum. We will show that the CDF and D0 collaborations have done their dijet analyses in ways which allow comparison of the results between the experiments. In addition, the dijet data sample is used by the D0 collaboration to place stringent limits on the energy scale of a possible quark compositeness interaction.