The WZ production cross section is measured by the CMS experiment at the CERN LHC in proton-proton collision data samples corresponding to integrated luminosities of 4.9 fb$^{-1}$ collected at $ \sqrt{s} = $ 7 TeV, and 19.6 fb$^{-1}$ at $ \sqrt{s} = $ 8 TeV. The measurements are performed using the fully-leptonic WZ decay modes with electrons and muons in the final state. The measured cross sections for 71 $
A measurement of the W boson pair production cross section in proton-proton collisions at [arrow]"s = 8 TeV is presented. The data we collected with the CMS detector at the LHC correspond to an integrated luminosity of 19.4 fb-1 . The W+W- candidates are selected from events with two charged leptons, electrons or muons, and large missing transverse energy. The measured W+W- cross section is 60.1 " 0.9 (stat) " 3.2 (exp) " 3.1 (theo) " 1.6 (lumi) pb = 60.1 " 4.8 pb, consistent with the standard model prediction. The W+W-cross sections are also measured in two different fiducial phase space regions. The normalized differential cross section is measured as a function of kinematic variables of the final-state charged leptons and compared with several perturbative QCD predictions. Limits on anomalous gauge couplings associated with dimension-six operators are also given in the framework of an effective field theory. Finally, the corresponding 95% confidence level intervals are -5.7
This study presents measurements of W±Z production in pp collisions at a center-of-mass energy of 8 TeV. The gauge bosons are reconstructed using their leptonic decay modes into electrons and muons. The data were collected in 2012 by the ATLAS experiment at the Large Hadron Collider and correspond to an integrated luminosity of 20.3 fb-1. The measured inclusive cross section in the detector fiducial region is ?W±Z→l'?ll = 35.1 ± 0.9(stat) ± 0.8(sys) ± 0.8(lumi) fb, for one leptonic decay channel. In comparison, the next-to-leading-order Standard Model expectation is 30.0 ± 2.1 fb. Cross sections for W+Z and W-Z production and their ratio are presented as well as differential cross sections for several kinematic observables. Limits on anomalous triple gauge boson couplings are derived from the transverse mass spectrum of the W±Z system. From the analysis of events with a W and a Z boson associated with two or more forward jets an upper limit at 95% confidence level on the W±Z scattering cross section of 0.63 fb, for each leptonic decay channel, is established, while the Standard Model prediction at next-to-leading order is 0.13 ± 0.01 fb. Limits on anomalous quartic gauge boson couplings are also extracted.
Measurements of W and Z boson production cross sections in pp collisions at [square root] s = 5.02TeV and [square root] s = 13TeV are presented. Data was collected by the CMS experiment at the LHC during low-pileup data taking periods in 2017. The corresponding integrated luminosity for the data is 299.1 ± 5 pb−1 ( [square root] s = 5.02TeV) and 199.3 ± 4 pb−1 ( [square root] s = 13TeV), with an average number of pile-up interactions [[mu] = 3 ([mu] = 2). Cross sections and cross section ratios are reported, with final states in electron and muon channels.
A measurement of inclusive W and Z production cross sections in pp collisions at sqrt(s)=7 TeV is presented. The electron and muon decay channels are analyzed in a data sample collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 inverse picobarns. The measured inclusive cross sections are sigma(pp-> WX) B(W-> l nu) = 10.30 +/- 0.02 (stat.) +/- 0.10 (syst.) +/- 0.10 (th.) +/- 0.41 (lumi.) nb and sigma(pp -> ZX) B(Z-> l+̂l-̂) = 0.974 +/- 0.007 (stat.) +/- 0.007 (syst.) +/- 0.018 (th.) +/- 0.039 (lumi.) nb, limited to the dilepton invariant mass range 60 to 120 GeV. The luminosity-independent cross section ratios are [sigma(pp->WX) B(W-> l nu)]/[sigma(pp-> ZX) B(Z->l+̂l-̂)] = 10.54 +/- 0.07 (stat.) +/- 0.08 (syst.) +/- 0.16 (th.) and [sigma(pp->W+̂X) B(W+̂ -> l+̂nu)] / [sigma(pp->W-̂ X) B(W-̂ -> l-̂ nu)] = 1.421 +/- 0.006 (stat.) +/- 0.014 (syst.) +/- 0.029 (th.). The measured values agree with next-to-next-to-leading order QCD cross section calculations based on recent parton distribution functions.
Measurements of inclusive W and Z boson production cross sections in pp collisions at sqrt(s)=7 TeV are presented, based on 2.9 inverse picobarns of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give sigma(pp to WX) times B(W to muon or electron + neutrino) = 9.95 \pm 0.07(stat.) \pm 0.28(syst.) \pm 1.09(lumi.) nb and sigma(pp to ZX) times B(Z to oppositely charged muon or electron pairs) = 0.931 \pm 0.026(stat.) \pm 0.023(syst.) \pm 0.102(lumi.) nb. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty of less than 4%, are also reported.
The production of W boson pairs in proton-proton collisions at √s = 8 TeV is studied using data corresponding to 20.3 fb-1 of integrated luminosity collected by the ATLAS detector during 2012 at the CERN Large Hadron Collider. The W bosons are reconstructed using their leptonic decays into electrons or muons and neutrinos. Events with reconstructed jets are not included in the candidate event sample. A total of 6636 WW candidate events are observed. Measurements are performed in fiducial regions closely approximating the detector acceptance. The integrated measurement is corrected for all acceptance effects and for the W branching fractions to leptons in order to obtain the total WW production cross section, which is found to be 71.1 ± 1.1(stat)-5.0+ 5.7(syst) ± 1.4(lumi) pb. This agrees with the next-to-next-to-leading-order Standard Model prediction of 63.2-1.4+1.6(scale) ± 1.2(PDF) pb. Fiducial differential cross sections are measured as a function of each of six kinematic variables. In conclusion, the distribution of the transverse momentum of the leading lepton is used to set limits on anomalous triple-gauge-boson couplings.
Measurements of the W± → l±[nu] and Z → l+l- production cross sections (where l± = e±, [mu]± ) in proton-proton collisions at √s = 13 TeV are presented using data recorded by the ATLAS experiment at the Large Hadron Collider, corresponding to a total integrated luminosity of 81 pb-1. The total inclusive W±-boson production cross sections times the single-lepton-flavour branching ratios are [sigma]Wtot+ =11.83 ± 0.02 (stat)±0.32 (sys)±0.25 (lumi) nb and [sigma]W-tot=8.79±0.02 (stat)±0.24 (sys)±0.18 (lumi) nb for W+ and W- , respectively.
A measurement of the W boson pair production cross section in proton-proton collisions at √ s = 8 TeV is presented. The data we collected with the CMS detector at the LHC correspond to an integrated luminosity of 19.4 fb-1 . The W+W- candidates are selected from events with two charged leptons, electrons or muons, and large missing transverse energy. The measured W+W- cross section is 60.1 ± 0.9 (stat) ± 3.2 (exp) ± 3.1 (theo) ± 1.6 (lumi) pb = 60.1 ± 4.8 pb, consistent with the standard model prediction. The W+W-cross sections are also measured in two different fiducial phase space regions. In addition, the normalized differential cross section is measured as a function of kinematic variables of the final-state charged leptons and compared with several perturbative QCD predictions. Limits on anomalous gauge couplings associated with dimension-six operators are also given in the framework of an effective field theory. Finally, the corresponding 95% confidence level intervals are -5.7 csubWWW/sub/?sup2/sup 5.9 TeVsup-2/sup, -11.4 csubW/sub/?sup2/sup 5.4 TeVsup-2/sup , -29.2 csubB
Cross sections for the production of a Z boson in association with jets in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}$=8 TeV are measured using a data sample collected by the CMS experiment at the LHC corresponding to 19.6 inverse femtobarns. Differential cross sections are presented as functions of up to three observables that describe the jet kinematics and the jet activity. Correlations between the azimuthal directions and the rapidities of the jets and the Z boson are studied in detail. The predictions of a number of multileg generators with leading or next-to-leading order accuracy are compared with the measurements. The comparison shows the importance of including multi-parton contributions in the matrix elements and the improvement in the predictions when next-to-leading order terms are included.
