Q(T) and phi* observables in Drell-Yan processes

We describe results on the phenomenology of electro-weak bosons produced in hadron-hadron collisions. In particular, we discuss the phi* variable, which enables us to probe the low-transverse-momentum region of lepton pairs produced via the Drell-Yan mechanism with unprecedented experimental accuracy. We describe state-of-the-art theoretical calculations for phi* and their comparison to Tevatron and LHC data.