Measurements of Inclusive W and Z Cross Sections in pp Collisions at sqrt(s)=7 TeV

TL;DR

This paper reports measurements of inclusive W and Z boson production cross sections in proton-proton collisions at 7 TeV, using CMS data, and compares them with advanced theoretical predictions, confirming their consistency.

Contribution

The study provides the first precise measurements of W and Z cross sections at 7 TeV with CMS, including ratios that reduce systematic uncertainties.

Findings

Measured cross sections agree with NNLO QCD predictions.

Ratios of W to Z cross sections have less than 4% systematic uncertainty.

Results validate theoretical models of electroweak boson production.

Abstract

Measurements of inclusive W and Z boson production cross sections in pp collisions at sqrt(s)=7 TeV are presented, based on 2.9 inverse picobarns of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give sigma(pp to WX) times B(W to muon or electron + neutrino) = 9.95 \pm 0.07(stat.) \pm 0.28(syst.) \pm 1.09(lumi.) nb and sigma(pp to ZX) times B(Z to oppositely charged muon or electron pairs) = 0.931 \pm 0.026(stat.) \pm 0.023(syst.) \pm 0.102(lumi.) nb. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty of less than 4%, are also reported.