High-Energy Limit of QCD beyond Sudakov Approximation

TL;DR

This paper analyzes the high-energy behavior of quark-mass suppressed amplitudes in QCD, deriving all-order resummation of double-logarithmic corrections influenced by soft quark exchange and color flow.

Contribution

It provides the first all-order resummation of mass-suppressed double-logarithmic corrections in high-energy QCD beyond the Sudakov approximation.

Findings

Resummation of double-logarithmic corrections for mass-suppressed amplitudes.

Explicit results for Higgs production via gluon fusion with light-quark loops.

Discovery of universality and relations between different gauge theories.

Abstract

We study the high-energy limit of the scattering amplitudes suppressed by the leading power of the quark mass in perturbative quantum chromodynamics. We prove the factorization and perform all-order resummation of the double-logarithmic radiative corrections which determine the asymptotic behavior of the amplitudes. In contrast to the Sudakov logarithms, the mass-suppressed double-logarithmic corrections are induced by soft quark exchange. The structure of the corrections and the asymptotic behavior of the amplitudes in this case crucially depend on the color flow in a given process and are determined by the eikonal color charge nonconservation. We present explicit results for the Higgs boson production in gluon fusion mediated by a light-quark loop and for the leading power-suppressed contributions to the quark form factors, which reveal "magical" universality. Nontrivial relations between the asymptotic behavior of different amplitudes and the amplitudes in different gauge theories are found.