Balitsky-Fadin-Kuraev-Lipatov approximation versus O( alpha s3) corrections to large-rapidity dijet production.

Abstract

We examine dijet production at large rapidity intervals at Fermilab Tevatron energies by comparing an exact scrO(${\mathrm{\ensuremath{\alpha}}}_{\mathit{s}}^{3}$) calculation with the Balitsky-Fadin-Kuraev-Lipatov (BFKL) approximation, which resums the leading powers of the rapidity interval y to all orders in ${\mathrm{\ensuremath{\alpha}}}_{\mathit{s}}$. We analyze the dependence of the exact scrO(${\mathrm{\ensuremath{\alpha}}}_{\mathit{s}}^{3}$) calculation on the jet cone size as a function of y, and use this cross section to define an ``effective rapidity'' y^ which reduces the error that the largy-y approximation induces on the kinematics. Using y^ in the BFKL resummation, we reexamine jet production at large transverse momenta and the transverse momentum decorrelation of the tagging jets. We find less dramatic, but still significant, effects than found previously using the large-y approximation.