Search for the Production of ZW and ZZ Boson Pairs Decaying Into Charged Leptons and Jets in Proton-antiproton Collisions at Sqrt[s]

Search for the Production of ZW and ZZ Boson Pairs Decaying Into Charged Leptons and Jets in Proton-antiproton Collisions at Sqrt[s]
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Release: 2013
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We present a measurement of the production cross section for ZW and ZZ boson pairs in final states with a pair of charged leptons, from the decay of a Z boson, and at least two jets, from the decay of a W or Z boson, using the full sample of proton-antiproton collisions recorded with the CDF II detector at the Tevatron, corresponding to 8.9 fb(̂-1) of integrated luminosity. We increase the sensitivity to vector boson decays into pairs of quarks using a neural network discriminant that exploits the differences between the spatial spread of energy depositions and charged-particle momenta contained within the jet of particles originating from quarks and gluons. Additionally, we employ new jet energy corrections to Monte Carlo simulations that account for differences in the observed energy scales for quark and gluon jets. The number of signal events is extracted through a simultaneous fit to the dijet mass spectrum in three classes of events: events likely to contain jets with a heavy-quark decay, events likely to contain jets originating from light quarks, and events that fail these identification criteria. We determine the production cross section to be 2.5 +2.0 -1.0 pb (

Measurement of the W±Z Boson Pair-production Cross Section in Pp Collisions at

Measurement of the W±Z Boson Pair-production Cross Section in Pp Collisions at
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Total Pages: 22
Release: 2016
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Here, the production of W±Z events in proton–proton collisions at a centre-of-mass energy of 13 TeV13 TeV is measured with the ATLAS detector at the LHC. The collected data correspond to an integrated luminosity of 3.2 fb–1. The W±Z candidates are reconstructed using leptonic decays of the gauge bosons into electrons or muons.

Measurement of the W±Z Boson Pair-production Cross Section in Pp Collisions at [mml

Measurement of the W±Z Boson Pair-production Cross Section in Pp Collisions at [mml
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Total Pages: 22
Release: 2016
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Here, the production of W±Z events in proton-proton collisions at a centre-of-mass energy of 13 TeV13 TeV is measured with the ATLAS detector at the LHC. The collected data correspond to an integrated luminosity of 3.2 fb-1. The W±Z candidates are reconstructed using leptonic decays of the gauge bosons into electrons or muons.

Electroweak Boson Pair Production at the Tevatron

Electroweak Boson Pair Production at the Tevatron
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Total Pages: 7
Release: 1994
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Preliminary results from CDF and D{O} on W[gamma], Z[gamma] and WW, WZ, ZZ boson pair production in √s = 1.8 TeV {anti p}-p collisions from the 1992--93 collider run are presented. Direct limits on CP-conserving and CP-violating WW[gamma], WWZ, ZZ[gamma] and Z[gamma][gamma] anomalous couplings have been obtained. The results are consistent with Standard Model expectations. In the static limit, the direct experimental limits on WW[gamma] and ZZ[gamma] anomalous couplings are related to bounds on the higher-order static (transition) EM moments of the W(Z) bosons. Expectations from the on-going and future Tevatron collider runs are discussed.

A Measurement of W Boson Pair Production in Pp Collisions at Sqrt(s)

A Measurement of W Boson Pair Production in Pp Collisions at Sqrt(s)
Author: Philip Sommer
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Release: 2016
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Zusammenfassung: In this thesis, measurements of the W boson pair production cross section in proton-proton collisions at a centre-of-mass energy of 8 TeV are presented. A dataset corresponding to an integrated luminosity of 22.3 /fb recorded by the ATLAS experiment in the year 2012 is used. The W bosons are identified by their decay products of exactly two leptons with opposite electrical charge, electrons or muons, and missing transverse momentum induced by their corresponding neutrinos. First, a measurement restricted to final states without hadronic jets is presented and differential fiducial cross sections, total cross sections and limits on anomalous triple gauge boson couplings are obtained. A second measurement of the fiducial cross section in association with exactly one hadronic jet is presented. The ratio of fiducial cross sections for different jet multiplicities is reported and the combined fiducial cross section is extrapolated to the total phase space.

Production of Gauge Bosons at the Tevatron

Production of Gauge Bosons at the Tevatron
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Release: 2001
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The CDF and D0 collaborations have used recent data taken at the Tevatron to perform QCD tests with W and Z bosons decaying leptonically. D0 measures the production cross section times branching ratio for W and Z bosons and determines the branching ratio B(W[yields] l[nu])= (10.43[+-] 0.44)% (l= e, [mu]). This also gives an indirect measurement of the total width of the W boson:[Gamma][sub W]= 2.16[+-] 0.09 GeV. The W cross section times branching ratio into tau leptons is measured to be[sigma]([anti p]p[yields] W+ X)B(W[yields][tau][nu])= 2.38[+-]0.13 nb, from which the ratio of the coupling constants is determined: g[sub[tau]][sup W]/g[sub e][sup W]= 1.004[+-] 0.019[+-] 0.026. D0's measurement of the differential d[sigma]/dP[sub T] distribution for the Z boson decaying to electrons, discriminates between different phenomenologic vector boson production models. CDF measures the cross section for the Drell-Yan continuum, and extracts improved limits on compositeness scales for quarks and leptons of[Lambda][sub ql][approximately] 3 - 6 TeV, depending on the model. Studies of W+ Jet production at CDF and D0 find that the QCD prediction underestimates the production rate of W+ 1 Jet events by about a factor of 2 as measured by both collaborations.