Measurement of the WW, WZ and ZZ cross sections at CMS

This note presents an updated measurement of W+W− production, and first measurements of WZ and ZZ production in proton proton collisions at √ s = 7 TeV with the CMS experiment at the Large Hadron Collider. Results are based on data corresponding to an integrated luminosity of 1.1 fb−1. The leptonic decay modes of the W and Z bosons are considered and the final states include electrons, muons, taus and missing transverse energy. The following cross sections are determined: σ(pp → W+W− + X) = 55.3 ± 3.3 (stat.) ± 6.9 (syst.) ± 3.3 ( lumi.) pb, σ(pp → WZ + X) = 17.0± 2.4 (stat.)± 1.1 (syst.)± 1.0 ( lumi.) pb and σ(pp → ZZ + X) = 3.8+1.5 −1.2 (stat.)± 0.2 (syst.)± 0.2 ( lumi.) pb. The measured cross sections are found to be consistent with the Standard Model.