Resummation for heavy quark and jet cross sections

TL;DR

This paper reviews the resummation of threshold logarithms in heavy quark and jet production, emphasizing the role of color exchange and anomalous dimension matrices at next-to-leading order.

Contribution

It introduces a comprehensive formulation for resummation at next-to-leading logarithmic accuracy, including new results for soft anomalous dimension matrices and their diagonalization.

Findings

Numerical results for top quark production at Tevatron.

Analytical expressions for one- and two-loop resummed cross sections.

Method for calculating resummed cross sections using anomalous dimension matrices.

Abstract

We review the resummation of threshold logarithms for heavy quark, dijet, direct photon, and W boson production cross sections in hadronic collisions. Beyond leading logarithms the resummed cross section is sensitive to the color exchange in the hard scattering. The resummation is formulated at next-to-leading logarithmic or higher accuracy in terms of anomalous dimension matrices which describe the factorization of soft gluons from the hard scattering. We give results for the soft anomalous dimension matrices at one loop for the full range of partonic subprocesses involved in heavy quark, dijet, direct photon, and W boson production. We discuss the general diagonalization procedure that can be implemented for the calculation of the resummed cross sections, and we give numerical results for top quark production at the Fermilab Tevatron. We also present analytical results for the one- and two-loop expansions of the resummed cross sections.