CDF Logo Measurement of WZ Production in WZ→lll&nu using 2 fb-1 of ppbar Collisions at √s=1.96 TeV CDF Logo

Contents

Introduction

In October 2006, CDF announced the first observation of WZ. This result was subsequently published as Phys. Rev. Lett. 98, 161801 (2007). We present an update to this analysis using 1.9 fb-1 of integrated luminosity. The WZ analysis uses a final state with 3 e,&mu leptons and missing tranverse energy (MET) from the unobserved neutrino in lepton decay of the W boson. At tree level, the WZ final state has the s-channel (left) and t-channel (right) contributions shown in these diagrams:




The s-channel diagram provides sensitivity to the WWZ vertex coupling. The WZ final state is unique among the triple gauge coupling (TGC) final states, providing access to this coupling separately from the WW&gamma coupling. TGCs which are absent in the Standard Model. The WZ final state in fully leptonic decay is a rare but clean experimental signatures that is sensitve to new physics contributions.

Summary of Results


TEX or GIF Signal and background expectations and observed events in the WZ signal region.

We measure:

consistent with the NLO cross section value of 3.7 ± 0.3 pb.

Systematic Uncertainties

consistent with the NLO cross section value of 3.7 ± 0.3 pb.

EPS or JPG Summary of single boson and diboson cross section measurements at the Tevatron at the time of WZ/ZZ blessing, including our results.

Analysis Methods

Selection





Signal and Control Regions

EPS or JPG MET vs. Dilepton Mass showing signal and control regions. Box plot of expected signal and backgrounds also shown.

Tables and Plots for Regions in W±Z0 Search Analysis

Summary of Control Region Results

EPS or GIF Summary of Dilepton and Trilepton Control Regions

N-1 Dilepton Invariant Mass Distributions

JPG or EPS MET distribution in Z mass JPG or EPS MET distribution (log scale) in Z mass

N-1 Missing Transverse Energy (MET) for Signal and Low MET Regions

JPG or EPS MET distribution in Z mass JPG or EPS MET distribution (log scale) in Z mass

Low MET Region


TEX or GIF Expectations and observed events in the Low Met region
TEX or GIF Expectations and observed events in the Low Met region, detailed by trilepton flavor categories.
JPG or EPS Trilepton flavor types for the Low MET region JPG or EPS Transverse mass of non-Z lepton and MET for the Low MET region
JPG or EPS Trilepton mass for the Low MET region JPG or EPS Angle between MET and nearest lepton or jet for the Low MET region
JPG or EPS Leading lepton transverse momentum for the Low MET region JPG or EPS Sub-leading lepton transverse momentum for the Low MET region
JPG or EPS Sub-Sub-Leading lepton transverse momentum for the Low MET region JPG or EPS Z transverse momentum for the Low MET region

Z Veto Region


TEX or GIF Expectations and observed events in the Low Met region
TEX or GIF Expectations and observed events in the Low Met region, detailed by trilepton flavor categories.
JPG or EPS Trilepton flavor types for the Z veto region JPG or EPS Transverse mass of non-Z lepton and MET for the Z veto region
JPG or EPS Trilepton mass for the Z veto region JPG or EPS Angle between MET and nearest lepton or jet for the Z veto region
JPG or EPS Leading lepton transverse momentum for the Z veto region JPG or EPS Sub-leading lepton transverse momentum for the Z veto region
JPG or EPS Sub-Sub-Leading lepton transverse momentum for the Z veto region JPG or EPS Z transverse momentum for the Z veto region

Signal Region


TEX or GIF Expectations and observed events in the Signal region for the W±Z0 search analysis.
JPG or EPS Trilepton flavor types for the Signal region JPG or EPS Transverse mass of non-Z lepton and MET for the Signal region
JPG or EPS Trilepton mass for the Signal region JPG or EPS Angle between MET and nearest lepton or jet for the Signal region
JPG or EPS Leading lepton transverse momentum for the Signal region JPG or EPS Sub-leading lepton transverse momentum for the Signal region
JPG or EPS Sub-Sub-Leading lepton transverse momentum for the Signal region JPG or EPS Z transverse momentum for the Signal region

Event Displays

W±Z0 Candidates



Mark Neubauer
Last modified: Wed Nov 8 23:11:17 CST 2006