Inclusive Double-Pomeron Exchange at the Fermilab Tevatron $\overline{p}p$ Collider

We report results from a study of events with a double-Pomeron exchange topology produced in $\overline{p}p$ collisions at $\sqrt{s}=1800\mathrm{G}\mathrm{e}\mathrm{V}$. The events are characterized by a leading antiproton and a large rapidity gap on the outgoing proton side. We find that the differential production cross section agrees in shape with predictions based on Regge theory and factorization, and that the ratio of double-Pomeron exchange to single diffractive production rates is relatively unsuppressed as compared to the $\mathcal{O}(10)$ suppression factor previously measured in single diffractive production.

Figure 1

Schematic diagrams and event topologies for (a) single diffraction, $\overline{p}+p\to \overline{p}+X$, and (b) double-Pomeron ($\mathbb{P}$) exchange, $\overline{p}+p\to \overline{p}+X+Y$; the shaded areas represent pseudorapidity regions of particle production.

Figure 2

(a) Distribution of antiproton fractional momentum loss ${\xi }_{\overline{p}}^X$ measured from calorimeter and beam-beam counter information for events in which the ${\xi }_{\overline{p}}^{\mathrm{R}\mathrm{P}\mathrm{S}}$ value measured by the Roman pot spectrometer is within $0.05<{\xi }_{\overline{p}}^{\mathrm{R}\mathrm{P}\mathrm{S}}<0.06$; the solid line is a Landau fit. (b) Median values ${\overline{\xi }}_{\overline{p}}^X$ obtained from Landau fits to data in different ${\xi }_{\overline{p}}^{\mathrm{R}\mathrm{P}\mathrm{S}}$ bins plotted versus ${\xi }_{\overline{p}}^{\mathrm{R}\mathrm{P}\mathrm{S}}$; a linear relationship is observed.

Figure 3

Distribution of proton fractional momentum loss ${\xi }_p^X$, measured from calorimeter and beam-beam counter information, for events with a leading antiproton of $0.035<{\xi }_{\overline{p}}^{\mathrm{R}\mathrm{P}\mathrm{S}}<0.095$ and $|t_{\overline{p}}|<1.0{\mathrm{G}\mathrm{e}\mathrm{V}}^2$; the curves are from a Monte Carlo simulation of SD (dotted line), DPE (dashed line) and total (solid line) contributions normalized to the data points; the DPE events were generated for ${\xi }_p<0.1$.