Probing BFKL Dynamics in the Dijet Cross Section at Large Rapidity Intervals in ppbar Collisions at sqrt{s}=1800 and 630 GeV

TL;DR

The dijet cross section for large Deltaeta in pp collisions at sqrt[s]=1800 and 630 GeV is measured using the D0 detector and the partonic cross section increases strongly with the size of Deltaeta.

Abstract

Inclusive dijet production at large pseudorapidity intervals (delta_eta) between the two jets has been suggested as a regime for observing BFKL dynamics. We have measured the dijet cross section for large delta_eta in ppbar collisions at sqrt{s}=1800 and 630 GeV using the DO detector. The partonic cross section increases strongly with the size of delta_eta. The observed growth is even stronger than expected on the basis of BFKL resummation in the leading logarithmic approximation. The growth of the partonic cross section can be accommodated with an effective BFKL intercept of a_{BFKL}(20GeV)=1.65+/-0.07.

Figures (1)

• Figure 1: The ratio of the dijet cross sections at $\sqrt{s}=1800$ and $630$ GeV for $\Delta\eta>1$ and $\Delta\eta>2$. The minimum jet $E_T$ is 20 GeV. The inner error bars on the data points represent statistical uncertainties; the outer bars represent statistical and uncorrelated systematic uncertainties added in quadrature. The error bars on the herwig predictions represent statistical uncertainties. The LO and BFKL predictions are analytical calculations.