Forskning ved Københavns Universitet - Københavns Universitet


Measurement of the W ¿ l¿ and Z/¿* ¿ ll production cross sections in proton-proton collisions at vs= 7 TeV with the ATLAS detector

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

First measurements of the W ¿ l¿ and Z/¿ * ¿ ll (l = e, µ) production cross sections in proton-proton collisions at s=7TeV are presented using data recorded by the ATLAS experiment at the LHC. The results are based on 2250 W ¿ l¿ and 179 Z/¿ * ¿ ll candidate events selected from a data set corresponding to an integrated luminosity of approximately 320 nb. The measured total W and Z/¿ *-boson production cross sections times the respective leptonic branching ratios for the combined electron and muon channels are Wtot. BR(W ¿ l¿) = 9.96 ± 0.23(stat) ± 0.50(syst) ± 1.10(lumi) nb and totZ BR(Z/¿ * ¿ ll) = 0.82 ± 0.06 (stat) ± 0.05 (syst) ± 0.09(lumi) nb (within the invariant mass window 66 < m ll < 116GeV). 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.
TidsskriftJournal of High Energy Physics (Online)
Udgave nummer12
Sider (fra-til)1-65
Antal sider65
StatusUdgivet - 4 dec. 2010

ID: 33261830