# $W$ and $Z$ boson production in 5.02 TeV $pp$ and $p$+Pb collisions with the ATLAS detector

## TL;DR

This paper reports measurements of $W$ and $Z$ boson production in 5.02 TeV proton-proton and proton-lead collisions using the ATLAS detector, comparing results to QCD models and exploring nuclear PDF modifications.

## Contribution

First measurements of vector boson production in $pp$ and $p$+Pb collisions at 5.02 TeV with detailed comparisons to theoretical models and PDF modifications.

## Key findings

- $Z$ boson cross section in $pp$ collisions measured as 590±9 (stat.)±12 (syst.)±32 (lumi.) pb.
- Model predictions with PDF modifications agree better with data.
- Indications of centrality dependence in PDF modifications in $p$+Pb collisions.

## Abstract

This proceeding reports the ATLAS results of measuring vector boson production in $pp$ and $p$+Pb collisions at the center-of-mass energy of 5.02~TeV per nucleon. $Z$ boson bosons are reconstructed via leptonic decays and results are presented as a function of $Z$-boson rapidity. $W$ boson bosons are identified by measuring leptons coming from $W$ boson decays and the results are presented as a function of lepton pseudorapidity. In $pp$ collisions $Z$ boson boson cross section in $|y_{Z}|<2.5$ is 590$\pm$9 (stat.)$\pm$12 (syst.)$\pm$32 (lumi.) pb. In $p$+Pb system kinematic distributions of $W$ boson and $Z$ boson bosons are compared to models based on NLO and NNLO QCD calculations using different PDF sets. Using PDF modification shows better agreement of the model and the data. Measurements done in different centrality intervals show that the PDF modification in $p$+Pb may have centrality dependence.