Collinear expansion for color singlet cross sections

Markus A Ebert,Bernhard Mistlberger,Gherardo Vita

doi:10.1007/jhep09(2020)181

Abstract

We demonstrate how to efficiently expand cross sections for color-singlet production at hadron colliders around the kinematic limit of all final state radiation being collinear to one of the incoming hadrons. This expansion is systematically improvable and applicable to a large class of physical observables. We demonstrate the viability of this technique by obtaining the first two terms in the collinear expansion of the rapidity distribution of the gluon fusion Higgs boson production cross section at next-to-next-to leading order (NNLO) in QCD perturbation theory. Furthermore, we illustrate how this technique is used to extract universal building blocks of scattering cross section like the N-jettiness and transverse momentum beam function at NNLO.

Highlights

Our knowledge of the structure of quantum field theory (QFT) is rapidly advancing
We demonstrate how to efficiently expand cross sections for color-singlet production at hadron colliders around the kinematic limit of all final state radiation being collinear to one of the incoming hadrons
We demonstrate the viability of this technique by obtaining the first two terms in the collinear expansion of the rapidity distribution of the gluon fusion Higgs boson production cross section at next-to-next-to leading order (NNLO) in QCD perturbation theory

Summary

Introduction

On the one hand this steady progress allows us to answer fundamental questions about the interactions of nature by deriving precise predictions for the outcome of scattering experiments that can be compared with experimental observation. Progress in QCD perturbation theory has allowed us to venture to predictions at nextto-next-to-next-to leading order (N3LO) in the strong coupling constant for select inclusive and differential cross sections at the Large Hadron Collider (LHC) [1,2,3,4,5,6,7,8,9]. Expanding the gluon fusion Higgs boson production cross section around the production threshold of the Higgs boson allowed for the computation of the first hadron collider cross section at N3LO in QCD perturbation theory [1]

Objectives

Discussion

Conclusion