  High-precision measurements of Standard Model processes provide information
on different aspects contributing to the process, such as parton distribution
functions, and comparisons with the current precision reached theoretically on
the calculations of the cross sections of such processes. This document
describes ATLAS measurements, performed at different centre-of-mass energies,
of vector boson (W and Z) cross sections and cross-section ratios. It also
discusses measurements of ratios of Z-boson and top-quark pair production cross
sections, which provide important information on the proton PDFs. Finally, a
measurement involving the di-lepton decay cahnnel of top-quark pairs at 8 TeV
is presented, because its direct sensitivity to the gluon PDF.
