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

## TL;DR

This paper assesses how recent precise LHC measurements of Z-boson transverse momentum distributions, combined with NNLO QCD predictions, improve the accuracy of parton distribution functions, especially reducing uncertainties in Higgs production cross sections.

## Contribution

It demonstrates the significant impact of incorporating latest $p_T^Z$ data into NNLO PDF fits, reducing uncertainties in key parton distributions and Higgs production predictions.

## Key findings

- Uncertainty in gluon-fusion Higgs cross section reduced by ~30%.
- Inclusion of $p_T^Z$ data improves PDF precision.
- Central values of PDFs remain stable after data inclusion.

## Abstract

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.