The transverse-momentum (QT) distribution of low-mass Drell-Yan pairs is calculated in QCD perturbation theory with all-order resummation of αs(αsln(QT2/Q2))n type terms. We demonstrate that the rapidity distribution of low-mass Drell-Yan pairs at large-enough transverse momentum is an advantageous source of constraints on the gluon distribution and its nuclear dependence. We argue that low-mass Drell-Yan pairs in the forward region provide a good and clean probe of small-x gluons at collider energies.
@article{arxiv.hep-ph/0409003,
title = {Probing small-$x$ gluons by low-mass Drell-Yan pairs at colliders},
author = {George Fai and Jianwei Qiu and Xiaofei Zhang},
journal= {arXiv preprint arXiv:hep-ph/0409003},
year = {2009}
}