Constraining parton distribution functions from neutral current Drell-Yan measurements

We study the cross section sigma and forward-backward asymmetry (A(FB)) in the process pp -> gamma, Z -> l(+)l(-) (with l = e, mu) for determinations of parton distribution functions (PDFs) of the proton. We show that, once mapped in the invariant mass of the dilepton final state, M(ll), both observables, sigma and A(FB), display a statistical error which is presently competitive with that assigned to the existing PDF sets and which will rapidly become smaller than the latter as the luminosity being accumulated at Run-II of the LHC grows. This statement is applicable to both on-peak and off-peak M(ll) regions, both (just) below and above it, thereby offering a means of constraining the quark PDFs over a sizable (x, Q(2)) range.