Measurement of the transverse momentum distribution of Z/gamma* bosons in proton-proton collisions at sqrt(s)=7 TeV with the ATLAS detector

TL;DR

This paper measures the transverse momentum distribution of Z/gamma* bosons in proton-proton collisions at 7 TeV using ATLAS data, comparing results with QCD predictions and event generators.

Contribution

It provides the first detailed measurement of Z/gamma* p_T distribution at 7 TeV with high precision, validating resummed QCD predictions against experimental data.

Findings

Resummed QCD combined with fixed order perturbative QCD agrees well with data.

Differential cross sections measured up to p_T^Z of 350 GeV.

Results support current QCD models and event generators.

Abstract

A measurement of the Z/gamma* transverse momentum (p_T^Z)) distribution in proton-proton collisions at sqrt(s)=7 TeV is presented using Z/gamma*->e+e- and Z/gamma*->mu+mu- decays collected with the ATLAS detector in data sets with integrated luminosities of 35 pb^-1 and 40 pb^-1, respectively. The normalized differential cross sections are measured separately for electron and muon decay channels as well as for their combination up to p_T^Z of 350 GeV for invariant dilepton masses 66 GeV<m_ll<116 GeV. The measurement is compared to predictions of perturbative QCD and various event generators. The prediction of resummed QCD combined with fixed order perturbative QCD is found to be in good agreement with the data.