Measurement of the W+W- Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Dilepton Events


S. Cabrera, S. Carron, S. Chuang, J. Deng, A. Goshaw, Y. Huang, M. Kruse, D. McGivern, D.Waters


For further details on all of the below, please refer to the published article.

[CDF ONLY : analysis details can be found in CDF-6909]


Physics Background
The measurement of the W pair production cross-section at the Tevatron provides an important test of the Standard Model. Leading order t-channel (~90%) and s-channel (~10%) diagrams are :

wwu
wws

Anomalous WW-gamma or WWZ couplings could result in an enhanced rate of W pair production. Standard Model WW production is also an important background for a heavy Higgs signal :

wwu

where the ggH vertex is via a quark loop, and is also a background to t-tbar production, and searches for new heavy gauge bosons.


Summary of Results
We find 17 dilepton candidate events compared to an expected background of 5.0(+2.2)(-0.8) events in a Run 2 data sample with a luminosity for WW events of approximately 184/pb. This results in a measured cross-section of:


dphi_met_lep


which is in agreement with a NLO (Next-to-Leading-Order) theoretical prediction of 12.4 ± 0.8 pb.


Summary of Event selection


Summary of Backgrounds, Expected Signal, and Data
dphi_met_lep


All channels combined; comparing this analysis with a "Lepton Plus Track" cross-check analysis :
dphi_met_lep




Kinematic Distributions
dphi_met_lep
eps
lepton_pt
eps
met
eps
dphi_met_lep
eps
lepton_pt
eps




Event Displays
e-e WW candidate
e-&mu WW candidate
&mu &mu WW candidate
eps
eps
eps



Last Updated February 9, 2005 (DSW)