Early Electroweak Measurements in CMS and ATLAS

Electroweak processes will be extremely important during the first phases of the LHC programme. They will be used to calibrate the ATLAS and CMS detectors, to understand the underlying event environment and to obtain background control samples for a large variety of possible new-physics signals. A progressive scenario can be envisaged: large statistics samples of W and Z decays into leptons will be available for an integrated luminosity of 10 /pb. W and Z production accompanied by jets will be studied with 100 /pb, diboson signals like pp->WZ will be observable with 150 /pb and a detailed understanding of the detector performance using ttbar events could be possible with luminosities as low as 300 /pb. Exploiting such a rich scenario is one of the objectives and challenges for the first year of LHC operation.