Investigating the Drell-Yan transverse momentum distribution in the color dipole approach

Abstract

We study the influence of unitarity corrections on the Drell-Yan transverse momentum distribution within the color dipole approach. These unitarity corrections are implemented through the multiple scattering Glauber- Mueller approach, which is contrasted with a phenomenological saturation model. The process is analyzed for the center of mass energies of the BNL Relativistic Heavy Ion Collider (RHIC, s=500 GeV) and of the CERN Large Hadron Collider (LHC, s=14 TeV). In addition, the results are extrapolated down to current energies of proton-proton collisions, where nonasymptotic corrections to the dipole approach are needed. It is also shown that, in the absence of saturation, the dipole approach can be related to the QCD Compton process.