Soft-gluon resummation for single-particle inclusive hadroproduction at high transverse momentum

Stefano Catani,Massimiliano Grazzini,Alessandro Torre

doi:10.1016/j.nuclphysb.2013.06.011

Stefano Catani, Massimiliano Grazzini + Show 1 more

Open Access

https://doi.org/10.1016/j.nuclphysb.2013.06.011

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Abstract

We consider the cross section for one-particle inclusive production at high transverse momentum in hadronic collisions. We present the all-order resummation formula that controls the logarithmically-enhanced perturbative QCD contributions to the partonic cross section in the threshold region, at fixed rapidity of the observed parton (hadron). The explicit resummation up to next-to-leading logarithmic accuracy is supplemented with the computation of the general structure of the near-threshold contributions to the next-to-leading order cross section. This next-to-leading order computation allows us to extract the one-loop hard-virtual amplitude that enters into the resummation formula. This is a necessary ingredient to explicitly extend the soft-gluon resummation beyond the next-to-leading logarithmic accuracy. These results equally apply to both spin-unpolarized and spin-polarized scattering processes.

Highlights

A well-known feature of QCD is that perturbative computations for hard-scattering processes are sensitive to soft-gluon effects
We have studied the corresponding partonic cross section in the threshold limit in which the final-state system that recoils against the triggered parton is constrained to have a small invariant mass
The result of this next-to-leading order (NLO) computation agrees with previous results in the literature, and it is presented here in a compact and process-independent form. This form is factorized in colour space and this allows us to explicitly disentangle colour interference effects

Summary

Introduction

A well-known feature of QCD is that perturbative computations for hard-scattering processes are sensitive to soft-gluon effects. Typical examples are the cross sections for the production of Drell–Yan lepton pairs and Higgs bosons In these cases, where only two QCD partons enter the hardscattering subprocess at the Born-level, the soft-gluon resummation formalism was established long ago [1,2,3], and explicit resummed results have been obtained up to next-to-next-to-leading logarithmic (NNLL) accuracy [4,5,6], and including still higher-order logarithmic terms that have been explicitly computed [7,8]. The content of the present paper aims at a twofold theoretical improvement on resummation for single-hadron inclusive production: we study soft-gluon resummation for the transverse momentum cross section at fixed rapidity of the observed hadron (parton), and we extend the logarithmic accuracy of resummation by explicitly computing a class of logarithmic terms beyond the NLL accuracy.

Single-particle cross section and notation

NLO results near partonic threshold

All-order soft-gluon resummation

Cross section integrated over the rapidity

Summary