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}
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}

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Published: 2009

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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 ± 47 events. The measured total cross section is [sigma](p{bar p} 2!WW− + X) = 12.1 ± 0.9 (stat){sub -1.4}{sup +1.6} (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.

Measurement of W-gamma and Z-gamma Production in Pp Collisions at Sqrt(s)
Measurement of W-gamma and Z-gamma Production in Pp Collisions at Sqrt(s)

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Published: 2011

Total Pages: 32

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A measurement of W-gamma and Z-gamma production in proton-proton collisions at sqrt(s) = 7 TeV is presented. Results are based on a data sample recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 36 inverse picobarns. The electron and muon decay channels of the W and Z are used. The total cross sections are measured for photon transverse energy>10 GeV and spatial separation from charged leptons in the plane of pseudorapidity and azimuthal angle>0.7, and with an additional dilepton invariant mass requirement of> 50 GeV for the Z-gamma process. The following cross section times branching fraction values are found: sigma(pp to W-gamma+X) B(W to lepton neutrino) = 56.3 +/- 5.0 (stat.) +/- 5.0 (syst.) +/- 2.3 (lumi.) pb and sigma(pp to Z-gamma+X) B}(Z to lepton lepton) = 9.4 +/- 1.0 (stat.) +/- 0.6 (syst.) +/- 0.4 (lumi.) pb. These measurements are in agreement with standard model predictions. The first limits on anomalous WW gamma, ZZ gamma, and Z gamma gamma trilinear gauge couplings at sqrt(s) = 7 TeV are set.

Search for Anomalous Couplings in Boosted $\mathrm{ WW/WZ }\to\ell\nu\mathrm{ Q \bar{q} }$ Production in Proton-proton Collisions at $\sqrt{s}
Search for Anomalous Couplings in Boosted $\mathrm{ WW/WZ }\to\ell\nu\mathrm{ Q \bar{q} }$ Production in Proton-proton Collisions at $\sqrt{s}

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Published: 2017

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This Letter presents a search for new physics manifested as anomalous triple gauge boson couplings in WW and WZ diboson production in proton-proton collisions. The search is performed using events containing a W boson that decays leptonically and a W or Z boson whose decay products are merged into a single reconstructed jet. The data, collected at sqrt(s) =8 TeV with the CMS detector at the LHC, correspond to an integrated luminosity of 19 inverse femtobarns. No evidence for anomalous triple gauge couplings is found and the following 95% confidence level limits are set on their values: lambda ([-0.011,0.011]), Delta kappa[gamma] ([-0.044,0.063]), and Delta g[1,Z] ([-0.0087,0.024]). These limits are also translated into their effective field theory equivalents: c[WWW]/ Lambda^2, ([-2.7,2.7] TeV^{-2}), c[B]/ Lambda^2, ([-14,17] TeV^{-2}), and c[W]/ Lambda^2, ([-2.0,5.7] TeV^{-2}).

Search for W Boson Pair Production in P[bar P] Collisions At[radical]
Search for W Boson Pair Production in P[bar P] Collisions At[radical]

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Published: 2001

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The results of a search for W boson pair production in p[bar p] collisions at[radical]s= 1.8 TeV with subsequent decay to dilepton (e[mu], ee, and[mu][mu]) channels are presented. One event is observed with an expected background of 0.56[plus-minus] 0.13 events with an integrated luminosity of approximately 14 pb[sup[minus]1]. Assuming equal strengths for the WWZ and WW[gamma] gauge boson coupling parameters[kappa] and[lambda], limits on the CP-conserving anomalous coupling constants are[minus]2.6