Session E13: W/Z Production

Search for $WW$ and $WZ$ production in charged lepton-neutrino plus dijet final state at CDF

We present a search for $WW$ and $WZ$ production in charged lepton-neutrino plus dijet final states produced in $p \bar{p}$ collisions with $\sqrt{s}=1.96$~TeV at the Fermilab Tevatron, using approximately 1.1 fb$^{-1}$ of data accumulated with the CDF II detector. This channel is yet to be observed in hadron colliders due to the large single $W$ plus jets background. However, this decay mode has a much larger branching fraction than the cleaner fully leptonic mode making it more sensitive to anomalous triple gauge couplings which typically manifest themselves at higher transverse $W$ momenta. Because the final state is topologically similar to associated production of a Higgs boson with a $W$ boson, the techniques developed in this analysis are also applicable in that search.   

Study of $W\gamma$ Production at the Tevatron

We report a measurement of $p\bar{p}$ $\to l^+ \nu$ $\gamma$ + X at $\sqrt{s}$ = 1.96 TeV produced at the Fermilab Tevatron using 1.2 $fb^{-1}$ of data collected by the CDF II detector. This channel has contributions from $W$ bosons produced with initial and final state photon radiation and from photons emitted due to the direct $WW\gamma$ coupling. Events are selected with electrons (muons) with $E_T$ $>$ 20 GeV ($p_T$ $>$ 20 GeV/c), and isolated photons with $E_T$ $>$ 15 GeV and $|$$\eta$$|$$<$2.8. The measured cross sections and kinematic distributions are compared to Standard Model electroweak predictions.   

Measurement of $Z\gamma$ Production at CDF

We present measurements of the $Z\gamma$ production cross section and kinematic distributions using 1~fb$^{-1}$ of luminosity collected by the CDF experiment in $p \bar{p}$ collisions at the Fermilab Tevatron in Run II. In the Standard Model this final state has contributions from $Z$ bosons produced with initial and final state photon radiation, and is sensitive to anomalous couplings of photons and $Z$ bosons due to possible contributions from physics beyond the Standard Model. Events are selected with two electrons or muons with transverse momenta $>20$~GeV, and isolated photons with $E_T>7$ GeV. The measured cross sections and kinematic distributions are compared to Standard Model predictions.   

Search for anomalous $ZZZ$ couplings in the dilepton+dijet final state at CDF

Using the di-lepton di-jet final state, we study $ZZZ$ anomalous triple neutral gauge couplings (aTGC) produced in $p \bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV at the Fermilab Tevatron collected with the CDF II detector. Specifically, we reconstruct two $Z$s, one decaying to two leptons and one decaying to two jets, and constrain aTGC based on the observed yield in $Z \rightarrow \ell \ell$ at high transverse momentum.   

First observation of $WZ$ production and the search for anomalous $WWZ$ couplings at CDF

We report the first observation of $WZ$ production in $p \bar{p}$ collisions at $\sqrt(s) = 1.96$ TeV at the Fermilab Tevatron using 1.1 $fb^{-1}$ of integrated luminosity collected by the CDF II detector. We observe 16 $WZ$ candidates passing the event selection with an expected background of 2.7 $\pm$ 0.4. A fit to the missing transverse energy distribution indicates an excess of events compared to background expectations corresponding to a 6.0 $\sigma$ observation of $WZ$ production. Additionally, we use the sample to set limits on anomalous triple gauge couplings and to search for new physics in the $WZ$ final state.   

WZ di-boson production cross section

The Standard Model (SM) predicts standard self-couplings of the bosons mediating electroweak interactions. Measuring these couplings is a powerful test of the SM's validity. I present a study searching for di-boson (WZ) final states using data collected by D0 experiment at the Tevatron, which collides protons and anti-protons at a center of mass energy of 1.96 TeV. For the first time we will use the final state where the Z boson decays to two charged leptons and the W boson decays to two quarks.   

A search for Z boson pair production at the Tevatron

We present a search for Z boson pair production decaying into leptons for one inverse femtobarn of data at $\sqrt{s}=1.96$ TeV with the Tevatron and the D0 detector.   

Measurement of Z boson production in association with Heavy Flavor jets at CDF

Production of Z boson in association with b or c quark is an important background to Higgs searches at the Tevatron collider. We use a newly developped algorithm to identify jets originating from b or c quarks and measure the Heavy Flavor content of jets produced in association with Z bosons.