Measurements of WW and WZ production in W + jets final states in p-pbar collisions

We study WW and WZ production with $l\nu qq$ ($l=e,\mu$) final states using data collected by the D0 detector at the Fermilab Tevatron Collider corresponding to 4.3 fb^-1 of integrated luminosity from p-pbar collisions at sqrt{s}=1.96 TeV. Assuming the ratio between the production cross sections $\sigma (WW)$ and $\sigma (WZ)$ as predicted by the standard model, we measure the total WV (V=W,Z) cross section to be $\sigma (WV)=19.6_{-3.0}^{+3.2}$ pb, and reject the background-only hypothesis at a level of 7.9 standard deviations. We also use b-jet discrimination to separate the WZ component from the dominant WW component. Simultaneously fitting WW and WZ contributions, we measure $\sigma (WW)=15.9_{-3.2}^{+3.7}$ pb and $\sigma(WZ) = 3.3^{+4.1}_{-3.3}$ pb, which is consistent with the standard model predictions.