Transverse momentum distributions in low-mass Drell-Yan lepton pair production at NNLO QCD

TL;DR

This paper analyzes how NNLO QCD corrections affect low-mass Drell-Yan lepton pair production's transverse momentum distributions, highlighting the importance of non-perturbative effects at fixed-target energies.

Contribution

It provides a detailed study of NNLO QCD corrections on low-mass Drell-Yan processes at different energies, emphasizing the limitations of perturbative QCD at fixed-target energies.

Findings

Perturbative convergence is satisfactory at collider energies.

Collider data are well-described by perturbative QCD.

Fixed-target energies require non-perturbative effects for accurate description.

Abstract

The production of lepton pairs at low invariant mass and finite transverse momentum resolves QCD dynamics at the boundary between the perturbative and non-perturbative domains. We investigate the impact of NNLO QCD corrections on these observables at energies corresponding to the BNL RHIC collider and to fixed-target experiments. Satisfactory perturbative convergence is observed in both cases. Only the collider data are found to be well-described by perturbative QCD, thus indicating the importance of non-perturbative effects in lepton-pair transverse momentum distributions at fixed target energies.