Search for new particles in the two-jet decay channel with the DØ detector

We present the results of a search for the production of new particles decaying into two jets in $\overline{p}p$ collisions at $\sqrt{s}=1.8\mathrm{}\mathrm{TeV},$ using the DØ 1992–1995 data set corresponding to ${109\mathrm{}\mathrm{pb}}^{-1}.$ We exclude at the 95% confidence level the production of excited quarks ${(q}^{*})$ with masses below 775 GeV/$c^2,$ the most restrictive limit to date. We also exclude standard-model-like $W^{\prime }$ ${(Z}^{\prime })$ bosons with masses between 300 and 800 GeV/$c^2$ (400 and 640 GeV/$c^2).\mathrm{}$ A $W^{\prime }$ boson with mass $<786\mathrm{}\mathrm{GeV}{/c}^2$ has been excluded by previous measurements, and our lower limit is therefore the most stringent to date.