Measurements of Inclusive W and Z Cross Sections in p-pbar Collisions at sqrt{s} =1.96 TeV

Measurements of inclusive W and Z boson production cross sections in pp collisions at √ s = 7 TeV are presented, based on 2.9 pb−1 of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give σ(pp → WX) × B(W → `ν) = 9.95 ± 0.07 (stat.) ± 0.28 (syst.) ± 1.09 (lumi.) nb and σ(pp → ZX) × B(Z → `+`−) = 0.931 ± 0.026 (stat.) ± 0.023 (syst.) ± 0.102 (lumi.) nb, where ` stands for either e or μ. 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. Submitted to the Journal of High Energy Physics ∗See Appendix A for the list of collaboration members ar X iv :1 01 2. 24 66 v2 [ he pex ] 2 0 Ja n 20 11