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

ANDUAGA, XABIER SEBASTIAN; THE ATLAS COLLABORATION

JOURNAL OF HIGH ENERGY PHYSICS - (Online)

SPRINGER

Año: 2010 vol. 2010 p. 1 - 65

1029-8479

First measurements of the W → lν and Z/γ∗ → ll (l = e,μ) production cross sections in proton- √proton collisions at    s = 7 TeV are presented using data recorded by the ATLAS experiment atthe LHC. The results are based on 2250 W → lν and 179 Z/γ∗ → ll candidate events selectedfrom a data set corresponding to an integrated luminosity of approximately 320 nb−1. The measuredtotal W and Z/γ∗-boson production cross sections times the respective leptonic branching ratios forthe combined electron and muon channels are σtot · BR(W → lν) = 9.96 ± 0.23(stat) ± 0.50(syst) W± 1.10(lumi) nb and σtot ∗ · BR(Z/γ∗ → ll) = 0.82±0.06(stat)±0.05(syst)±0.09(lumi) nb (within Z/γthe invariant mass window 66 < mll < 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 + and W − 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.