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Languages : en
Pages : 45
Book Description
Measurement of the W Gamma and Z Gamma Inclusive Cross Sections in Pp Collisions at $\sqrt{s}$
Author: Measurement of W-gamma and Z-gamma Production in Pp Collisions at Sqrt(s)
Author: Publisher:
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Languages : en
Pages : 32
Book Description
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.
Measurement of the Inclusive $W\̂pm$ and Z/Gamma Cross Sections in the Electron and Muon Decay Channels in $Pp$ Collisions at $\sqrt{s}
Author: Measurement of the Inclusive W and Z Production Cross Sections in Pp Collisions at $ \sqrt {s}
Author: Publisher:
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Category :
Languages : en
Pages :
Book Description
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.
Measurement of the Z[gamma] Production Cross Section in Pp Collisions at 8 TeV and Search for Anomalous Triple Gauge Boson Couplings
![Measurement of the Z[gamma] Production Cross Section in Pp Collisions at 8 TeV and Search for Anomalous Triple Gauge Boson Couplings PDF](https://books.google.com/books/content/images/frontcover/EEJ1nQAACAAJ?fife=w80-h100)
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 39
Book Description
The cross section for the production of Z[gamma] in proton-proton collisions at 8 TeV is measured based on data collected by the CMS experiment at the LHC corresponding to an integrated luminosity of 19.5 fb-1. Events with an oppositely-charged pair of muons or electrons together with an isolated photon are selected. Furthermore, the differential cross section as a function of the photon transverse momentum is measured inclusively and exclusively, where the exclusive selection applies a veto on central jets. These observed cross sections are compatible with the expectations of next-to-next-to-leading-order quantum chromodynamics. As a result, limits on anomalous triple gauge couplings of ZZ[gamma] and Z[gamma][gamma] are set that improve on previous experimental results obtained with the charged lepton decay modes of the Z boson.
Measurements of Inclusive W and Z Cross Sections in Pp Collisions at Sqrt(s)
Author: Publisher:
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Category :
Languages : en
Pages : 38
Book Description
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.
Measurement of the $ \mathrm{ Z } \gamma \rightarrow \nu \bar{\nu} \gamma$ Production Cross Section in Pp Collisions at $\sqrt{s}
Author: Publisher:
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Languages : en
Pages :
Book Description
A measurement of the Z gamma to nu nu-bar gamma production cross section in pp collisions at sqrt(s) = 8 TeV is presented, using data corresponding to an integrated luminosity of 19.6 inverse-femtobarns collected with the CMS detector at the LHC. This measurement is based on the observation of events with large missing energy and with a single photon with transverse momentum above 145 GeV and absolute pseudorapidity in the range
Electroweak Physics
Author: Publisher:
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Languages : en
Pages :
Book Description
The Standard Model predictions for W[gamma] and Z[gamma] production are tested using an integrated luminosity of 200 pb−1 of p{bar p} collision data collected at the Collider Detector at Fermilab. The cross sections are measured by selecting leptonic decays of the W and Z bosons, and photons with transverse energy E{sub T}> 7 GeV that are well separated from leptons. The production cross sections and kinematic distributions for the W[gamma] and Z[gamma] data are compared to SM predictions.
Measurement of the Z[gamma][gamma] Production Cross Section at Proton-proton Collisions with the CMS Experiment
![Measurement of the Z[gamma][gamma] Production Cross Section at Proton-proton Collisions with the CMS Experiment PDF](https://books.google.com/books/content/images/frontcover/qbWdAQAACAAJ?fife=w80-h100)
Author: Sachiko Toda McBrideMeasurements of the $\mathrm{ Pp \to W \gamma\gamma }$ and $\mathrm{ Pp \to Z \gamma\gamma }$ Cross Sections and Limits on Anomalous Quartic Gauge Couplings at $\sqrt{s}
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Measurements are presented of $ \mathrm{ W \gamma\gamma } $ and $ \mathrm{ Z \gamma\gamma } $ production in proton-proton collisions. Fiducial cross sections are reported based on a data sample corresponding to an integrated luminosity of 19.4 fb$^{-1}$ collected with the CMS detector at a center-of-mass energy of 8 TeV. Signal is identified through the $\mathrm{ W } \to \ell\nu$ and $\mathrm{ Z }\to\ell\ell$ decay modes, where $\ell$ is a muon or an electron. The production of $ \mathrm{ W \gamma\gamma } $ and $ \mathrm{ Z \gamma\gamma } $, measured with significances of 2.6 and 5.9 standard deviations, respectively, is consistent with standard model predictions. In addition, limits on anomalous quartic gauge couplings in $ \mathrm{ W \gamma\gamma } $ production are determined in the context of a dimension-8 effective field theory.