The qT spectrum of the Higgs boson at the LHC in QCD perturbation theory

G Bozzi,S Catani,D De Florian,M Grazzini

doi:10.1016/s0370-2693(03)00656-7

Abstract

We consider the transverse-momentum (qT) distribution of Higgs bosons produced at hadron colliders. We use a formalism that uniformly treats both the small-qT and large-qT regions in QCD perturbation theory. At small qT (qT⪡MH, MH being the mass of the Higgs boson), we implement an all-order resummation of logarithmically-enhanced contributions up to next-to-next-to-leading logarithmic accuracy. At large qT (qT≳MH), we use fixed-order perturbation theory up to next-to-leading order. The resummed and fixed-order approaches are consistently matched by avoiding double-counting in the intermediate-qT region. In this region, the introduction of unjustified higher-order terms is avoided by imposing unitarity constraints, so that the integral of the qT spectrum exactly reproduces the perturbative result for the total cross section up to next-to-next-to-leading order. Numerical results at the LHC are presented. These show that the main features of the qT distribution are quite stable with respect to perturbative QCD uncertainties.

Highlights

The Standard Model (SM) of electroweak interactions has been spectacularly confirmed by experimental data
The next-to-leading order (NLO) perturbative corrections to the total cross section for Higgs boson production via gluon fusion were computed in Ref. [6] and [7] and were found to be large, casting doubts upon the reliability of the perturbative expansion
In the large-Mt limit, the next-to-next-to-leading order (NNLO) contribution has been computed in Ref. [8] and still higherorder contributions have been evaluated in Ref. [9] by implementing soft-gluon resummation

Summary

Introduction

The Standard Model (SM) of electroweak interactions has been spectacularly confirmed by experimental data. The next-to-leading order (NLO) perturbative corrections to the total cross section for Higgs boson production via gluon fusion were computed in Ref. When studying the qT distribution of the Higgs boson in QCD perturbation theory, it is convenient to start by considering separately the large-qT and small-qT regions.

Results

Conclusion