Super-Leading Logarithms in Top-Quark Pair Production at Hadron Colliders

TL;DR

This paper extends the understanding of super-leading logarithms in hadron collisions to include massive final states, deriving new anomalous dimensions and analyzing their impact on top-quark pair production.

Contribution

It introduces a formalism for super-leading logarithms with massive states, deriving anomalous dimensions and performing resummation for top-quark pair production.

Findings

Identification of an additional Coulomb phase causing super-leading logs

Systematic leading-logarithmic resummation for 2→M processes

Numerical analysis showing impact on top-quark pair production

Abstract

To date, the appearance and resummation of "super-leading" logarithms in hadron-hadron collisions has been studied only for massless parton states. We extend the formalism to include an arbitrary number of massive final states. We derive the corresponding anomalous dimension and identify an additional Coulomb phase that gives rise to a new source of super-leading logarithms. We then perform a systematic leading-logarithmic resummation of these contributions for $2\to M$ processes. Finally, we analyze the numerical impact in partonic scattering processes for $t\bar{t}$ production, including a treatment of the Sommerfeld enhancement observed near threshold.