Drell-Yan phenomenology in the color dipole picture revisited

An extensive phenomenological study of the Drell-Yan (DY) process in pp collisions at various energies is performed in the color dipole framework. Besides previously studied γ∗ production we also include the Z0 contribution relevant at large dilepton invariant masses. We investigate the DY cross section differential in invariant mass, rapidity and transverse momentum of the dilepton pair in pp collisions at the RHIC and LHC. We consider three different phenomenological models for the dipole cross section and find a reasonable agreement with the available data. As a further test of the color dipole formalism, we also study the correlation function in azimuthal angle between the dilepton pair and a forward pion Δφ for different energies, dilepton rapidities and invariant masses. The characteristic double-peak structure of the correlation function around Δφ≃π found for very forward pions and low-mass dilepton pairs is sensitive to the saturation effects and can be tested by future DY measurements in pp collisions.