Measurement of Diffractive Dijet Production at the Fermilab Tevatron

Abstract

We report the observation and measurement of the rate of diffractive dijet production at the Fermilab Tevatron $\overline{p}p$ collider at $\sqrt{s}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.8\mathrm{TeV}$. In events with two jets of ${E}_{T}>20\mathrm{GeV}$, $1.8<|\ensuremath{\eta}|<3.5$, and ${\ensuremath{\eta}}_{1}{\ensuremath{\eta}}_{2}>0$, we find that the diffractive to nondiffractive production ratio is ${R}_{\mathrm{JJ}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}[0.75\ifmmode\pm\else\textpm\fi{}0.05(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.09(\mathrm{syst})]%$. By comparing this result, in combination with our measured rate for diffractive $W$ boson production reported previously, with predictions based on a hard partonic pomeron structure, we determine the pomeron gluon fraction to be ${f}_{g}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.7\ifmmode\pm\else\textpm\fi{}0.2$.