Higgs boson production at the LHC using the qT subtraction formalism at N3LO QCD

Leandro Cieri,Alexander Huss,Xuan Chen,E W N Glover,Thomas Gehrmann

doi:10.1007/jhep02(2019)096

Abstract

We consider higher-order QCD corrections to Higgs boson production through gluon-gluon fusion in the large top quark mass limit in hadron collisions. We extend the transverse-momentum (qT ) subtraction method to next-to-next-to-next-to-leading order (N3LO) and combine it with the NNLO Higgs-plus-jet calculation to numerically compute differential infrared-safe observables at N3LO for Higgs boson production in gluon fusion. To cancel the infrared divergences, we exploit the universal behaviour of the associated qT distributions in the small-qT region. We document all the necessary ingredients of the transverse-momentum subtraction method up to N3LO. The missing third-order collinear functions, which contribute only at qT = 0, are approximated using a prescription which uses the known result for the total Higgs boson cross section at this order. As a first application of the third-order qT subtraction method, we present the N3LO rapidity distribution of the Higgs boson at the LHC.

Highlights

Extending the perturbative accuracy of QCD calculations to one order higher implies developing new methods and techniques to achieve the cancellation of infrared (IR) divergences that appear at intermediate steps of the calculations
We extend the transverse-momentum subtraction method to next-to-next-to-next-to-leading order (N3LO) and combine it with the NNLO Higgs-plus-jet calculation to numerically compute differential infrared-safe observables at N3LO for Higgs boson production in gluon fusion
The NNLO cross sections computed with the qT subtraction method are obtained using qTcut = 1 GeV, i.e. the variation of this parameter in the N3LO cross section is considered at N3LO-only

Summary

Introduction

Extending the perturbative accuracy of QCD calculations to one order higher implies developing new methods and techniques to achieve the cancellation of infrared (IR) divergences that appear at intermediate steps of the calculations. In view of the impressive and continuously improving quality of the measurements performed at the LHC, even NNLO accuracy is in some cases not sufficient to match the demands of the LHC data These are processes in which the size of the NLO corrections are comparable with the LO, and where the NNLO corrections still exhibit large effects such that the size of the theoretical uncertainties remains larger than the experimental uncertainties. In this paper we extend the qT subtraction method at N3LO to compute Higgs boson production differentially in the Higgs boson rapidity at N3LO accuracy. The method is illustrated in its general form and spe-

Objectives

Results

Conclusion