IR-Improved DGLAP Theory: Kernels, Parton Distributions, Reduced Cross Sections

TL;DR

This paper introduces an IR-improved DGLAP theory using amplitude-based resummation, leading to new kernels and parton distributions that maintain perturbative QCD results at high momentum transfers, with implications for LHC physics.

Contribution

It presents a novel IR-improvement of DGLAP theory through amplitude-based resummation, resulting in new kernels and distributions consistent with existing QCD results.

Findings

New IR-improved kernels and parton distributions are derived.

The IR-improvement preserves the perturbative QCD results at large momentum transfers.

Phenomenological examples demonstrate the impact of IR-improvement for LHC applications.

Abstract

It is shown that exact, amplitude-based resummation allows IR-improvement of the usual DGLAP theory. This results in a new set of kernels, parton distributions and attendant reduced cross sections, so that the QCD perturbative result for the respective hadron-hadron or lepton-hadron cross section is unchanged order-by-order in $\alpha_s$ at large squared-momentum transfers. We compare these new objects with their usual counter-parts and illustrate the effects of the IR-improvement in some phenomenological cases of interest with an eye toward precision applications in LHC physics scenarios.