Measurement of the $W^+W^-$ Production Cross Section and Search for Anomalous $WW\gamma$ and $WWZ$ Couplings in $p \bar p$ Collisions at $\sqrt{s} = 1.96$ TeV

TL;DR

This paper reports the most precise measurement of W boson pair production cross section at 1.96 TeV and sets new limits on anomalous WWγ and WWZ couplings using data from the CDF II detector.

Contribution

It provides the most accurate W pair production cross section measurement and the most sensitive constraints on anomalous gauge couplings at Tevatron energies.

Findings

Measured cross section: 12.1 ± 0.9 (stat) +1.6/-1.4 (syst) pb

Observed 654 W pair candidate events

Set new limits on anomalous WWγ and WWZ couplings

Abstract

This Letter describes the current most precise measurement of the $W$ boson pair production cross section and most sensitive test of anomalous $WW\gamma$ and $WWZ$ couplings in $p \bar p$ collisions at a center-of-mass energy of 1.96 TeV. The $WW$ candidates are reconstructed from decays containing two charged leptons and two neutrinos, where the charged leptons are either electrons or muons. Using data collected by the CDF II detector from 3.6 fb$^{-1}$ of integrated luminosity, a total of 654 candidate events are observed with an expected background contribution of $320 \pm 47$ events. The measured total cross section is $\sigma (p \bar p \to W^+ W^- + X) = 12.1 \pm 0.9 \textrm{(stat)} ^{+1.6}_{-1.4} \textrm{(syst)}$ pb, which is in good agreement with the standard model prediction. The same data sample is used to place constraints on anomalous $WW\gamma$ and $WWZ$ couplings.