Measurement of the WW plus WZ Production Cross Section Using the lepton plus jets Final State at CDF II

We report two complementary measurements of the 𝑊⁢𝑊 +𝑊⁢𝑍 cross section in the final state consisting of an electron or muon, missing transverse energy, and jets, performed using 𝑝⁢ ‾‾‾ 𝑝 collision data at √𝑠 =1.96  TeV collected by the CDF II detector. The first method uses the dijet invariant mass distribution while the second more sensitive method uses matrix-element calculations. The result from the second method has a signal significance of 5.4⁢𝜎 and is the first observation of 𝑊⁢𝑊 +𝑊⁢𝑍 production using this signature. Combining the results gives 𝜎𝑊⁢𝑊+𝑊⁢𝑍 =16.0 ±3.3  pb , in agreement with the standard model prediction.