Measurement of the pp{yields}WZ+X cross section at {radical}(s)=1.96 TeV and limits on WWZ trilinear gauge couplings

We present measurements of the process pp{yields}WZ+X{yields}l{sup '}{nu}{sub l{sup '}}ll at {radical}(s)=1.96 TeV, where l and l{sup '} are electrons or muons. Using 1 fb{sup -1} of data from the D0 experiment, we observe 13 candidates with an expected background of 4.5{+-}0.6 events and measure a cross section {sigma}(WZ)=2.7{sub -1.3}{sup +1.7} pb. From the number of observed events and the Z boson transverse momentum distribution, we limit the trilinear WWZ gauge couplings to -0.17{<=}{lambda}{sub Z}{<=}0.21({delta}{kappa}{sub Z}=0) at the 95% C.L. for a form factor scale {lambda}=2 TeV. Further, assuming that {delta}g{sub 1}{sup Z}={delta}{kappa}{sub Z}, we find -0.12{<=}{delta}{kappa}{sub Z}{<=}0.29({lambda}{sub Z}=0) at the 95% C.L. These are the most restrictive limits on the WWZ couplings available to date.