Measurement of the W-->lnu and Z/g*--> ll production cross sections in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector

THE ATLAS COLL. , G. AAD; MARIA TERESA DOVA ET AL.

JOURNAL OF HIGH ENERGY PHYSICS

SPRINGER

Lugar: Berlin; Año: 2010 vol. 1012 p. 60 - 110

1126-6708

First measurements of the W -->lnu and Z/g --> ll (l = e;m) production cross sections in protonproton collisions at 7 TeV are presented using data recorded by the ATLAS experiment at the LHC. The results are based on 2250 W -->lnu and 179 Z/g -->ll candidate events selected from a data set corresponding to an integrated luminosity of approximately 320 nb-11. The measured total W and Z/g-boson production cross sections times the respective leptonic branching ratios for the combined electron and muon channels are Sigma_totX
BR(W -->ln) = 9.96  0.23(stat)  0.50(syst)  1.10(lumi) nb and sigma_tot Z/g
BR(Z/g-->ll) = 0.82 +-0.06(stat)+-0.05(syst)+- 0.09(lumi) nb (within the invariant mass window 66 < m< 116 GeV). The W/Z cross-section ratio is measured to be 11.7  0.9(stat)  0.4(syst). In addition, measurements of the W+ andW-production cross sections and of the lepton charge asymmetry are reported. Theoretical predictions based on NNLO QCD calculations are found to agree with the measurements.