Measurements of W(+/-)Z production cross sections in pp collisions at root s=8 TeV with the ATLAS detector and limits on anomalous gauge boson self-couplings

This paper presents measurements of WZ production in pp collisions at a center-of-mass energy of 8 TeV. The gauge bosons are reconstructed using their leptonic decay modes into electrons and muons. The data were collected in 2012 by the ATLAS experiment at the Large Hadron Collider and correspond to an integrated luminosity of 20.3  fb−1. The measured inclusive cross section in the detector fiducial region with 3 leptons is 35.1±0.9⁢(stat)±0.8⁢(sys)±0.8⁢(lumi)  fb, for one leptonic decay channel. In comparison, the next-to-leading-order Standard Model expectation is 30.0±2.1  fb. Cross sections for the production of WZ with a positive W and negative W, and their ratio are presented as well as differential cross sections for several kinematic observables. Limits on anomalous triple gauge boson couplings are derived from the transverse mass spectrum of the WZ system. From the analysis of events with a W and a Z boson associated with two or more forward jets an upper limit at 95% confidence level on the WZ scattering cross section of 0.63 fb, for each leptonic decay channel, is established, while the Standard Model prediction at next-to-leading order is 0.13±0.01  fb. Limits on anomalous quartic gauge boson couplings are also extracted.