The impact of the LHC Z-boson transverse momentum data on PDF determinations

The LHC has recently released precise measurements of the transverse momentum distribution of the Z-boson that provide a unique constraint on the structure of the proton. Theoretical developments now allow the prediction of these observables through next-to-next-to-leading order (NNLO) in perturbative QCD. In this work we study the impact of incorporating these latest advances into a determination of parton distribution functions (PDFs) through NNLO including the recent ATLAS and CMS 7 TeV and 8 TeV p_T ^Z data. We investigate the consistency of these measurements in a global fit to the available data and quantify the impact of including the p_T ^Z distributions on the PDFs. The inclusion of these new data sets significantly reduces the uncertainties on select parton distributions and the corresponding parton-parton luminosities. In particular, we find that the p_T ^Z data ultimately leads to a reduction of the PDF uncertainty on the gluon-fusion and vector-boson fusion Higgs production cross sections by about 30%, while keeping the central values nearly unchanged.