High-order corrections and subleading logarithms for top quark production
Nikolaos Kidonakis
TL;DR
The paper develops high-order threshold expansions for top-quark production in hadronic collisions using resummation, deriving expressions through N^4LO with NNLL accuracy. It analyzes subleading logarithms and resummation prescriptions, demonstrating that improper inclusion of unphysical terms can distort fixed-order results. Numerical studies for Tevatron energies show that NNLO-NNLL corrections significantly increase the total cross section and greatly reduce factorization-scale dependence, with predictions for differential distributions. The work highlights both the potential and the pitfalls of threshold resummation, arguing for careful handling of subleading terms and recommending NNLO as a reliable benchmark for phenomenology.
Abstract
We derive high-order threshold corrections for top quark production in hadronic collisions from resummation calculations. We present analytical expressions for the cross section through next-to-next-to-next-to-next-to-leading order (N^4LO) and next-to-next-to-leading logarithmic accuracy. Special attention is paid to the role of subleading logarithms and how they relate to the convergence of the perturbation series and differences between various resummation prescriptions. It is shown that care must be taken to avoid unphysical terms in the expansions. Numerical results are presented for top quark production at the Tevatron. We find sizeable increases to the total cross section and differential distributions and a dramatic reduction of the factorization scale dependence relative to next-to-leading order.