Beam Thrust Cross Section for Drell-Yan Production at Next-to-Next-to-Leading-Logarithmic Order

Abstract

At the LHC and Tevatron strong initial-state radiation (ISR) plays an important role. It can significantly affect the partonic luminosity available to the hard interaction or contaminate a signal with additional jets and soft radiation. An ideal process to study ISR is isolated Drell-Yan production, pp→Xℓ+ℓ- [pp→ l superscript + l superscript -] without central jets, where the jet veto is provided by the hadronic event shape beam thrust τB [T subscript B]. Most hadron collider event shapes are designed to study central jets. In contrast, requiring τB≪1 [T subscript B <<1] provides an inclusive veto of central jets and measures the spectrum of ISR. For τB≪1 [T subscript B <<1] we carry out a resummation of αsnln⁡mτB [alpha superscript n subscript s 1 n superscript m T subscript B] corrections at next-to-next-to-leading-logarithmic order. This is the first resummation at this order for a hadron-hadron collider event shape. Measurements of τB [T subscript B] at the Tevatron and LHC can provide crucial tests of our understanding of ISR and of τB’s [T subscript B]'s utility as a central jet veto.