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Title: Measurement of the $W^+W^-$ cross section in pp collisions at $$\sqrt{s}$$ = 8 TeV and limits on anomalous gauge couplings

Abstract

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 < c WWW2 < 5.9 TeV -2, -11.4 < c W2 < 5.4 TeV -2 , -29.2 < c B2 < 23.9 TeV -2, in the HISZ basis.

Authors:
 [1]
  1. Yerevan Physics Inst. (YerPhI) (Armenia). et al.
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1221302
Report Number(s):
FERMILAB-PUB-15-330-CMS
Journal ID: ISSN 1434-6044; arXiv eprint number arXiv:1507.03268; TRN: US1601619
Grant/Contract Number:
AC02-07CH11359; AC02-05CH11231
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
European Physical Journal. C, Particles and Fields
Additional Journal Information:
Journal Volume: 76; Journal Issue: 7; Journal ID: ISSN 1434-6044
Publisher:
Springer
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Khachatryan, Vardan. Measurement of the $W^+W^-$ cross section in pp collisions at $\sqrt{s}$ = 8 TeV and limits on anomalous gauge couplings. United States: N. p., 2016. Web. doi:10.1140/epjc/s10052-016-4219-1.
Khachatryan, Vardan. Measurement of the $W^+W^-$ cross section in pp collisions at $\sqrt{s}$ = 8 TeV and limits on anomalous gauge couplings. United States. doi:10.1140/epjc/s10052-016-4219-1.
Khachatryan, Vardan. 2016. "Measurement of the $W^+W^-$ cross section in pp collisions at $\sqrt{s}$ = 8 TeV and limits on anomalous gauge couplings". United States. doi:10.1140/epjc/s10052-016-4219-1. https://www.osti.gov/servlets/purl/1221302.
@article{osti_1221302,
title = {Measurement of the $W^+W^-$ cross section in pp collisions at $\sqrt{s}$ = 8 TeV and limits on anomalous gauge couplings},
author = {Khachatryan, Vardan},
abstractNote = {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 < cWWW/Λ2 < 5.9 TeV-2, -11.4 < cW/Λ2 < 5.4 TeV-2 , -29.2 < cB/Λ2 < 23.9 TeV-2, in the HISZ basis.},
doi = {10.1140/epjc/s10052-016-4219-1},
journal = {European Physical Journal. C, Particles and Fields},
number = 7,
volume = 76,
place = {United States},
year = 2016,
month = 7
}

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Cited by: 4works
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  • The standard model (SM) of particle physics has been extensively tested in the past three decades and is found to be in excellent agreement with experimental observations. It is widely assumed, however, that the SM is only a low energy approximation of a more general theory. Therefore, any significant deviation from the SM predictions yields information on the nature of a more fundamental theory. Production of WZ pairs is the least studied diboson process within the SM, as it is a charged final state and can only be produced at hadron colliders. A detailed study of this process probes themore » electroweak sector of the SM. In addition, searches for new phenomena in the production of heavy gauge boson pairs are interesting, as many extensions of the SM predict 1-4 additional heavy gauge bosons that can decay into a WZ boson pairs.« less
  • © 2016, CERN for the benefit of the CMS collaboration. A measurement of the W boson pair production cross section in proton-proton collisions at √s = 8 TeV is presented. The data collected with the CMS detector at the LHC correspond to an integrated luminosity of 19.4fb-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 modelmore » 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. The corresponding 95 % confidence level intervals are -5.7 < c WWW/Λ 2 < 5.9TeV -2 , -11.4 < c W/Λ 2 < 5.4TeV -2 , -29.2 < c B/Λ 2 < 23.9TeV -2 , in the HISZ basis.« less
  • 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 fbmore » $$^{-1}$$ 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 $$ < m_{\mathrm{ Z }} < $$ 111 GeV are $$\sigma(\mathrm{ p }\mathrm{ p }\to\mathrm{ W }\mathrm{ Z };\ \sqrt{s} = 7\, \mathrm{TeV}) =$$ 20.14 $$\pm$$ 1.32 (stat) $$\pm$$ 1.13 (syst) $$\pm$$ 0.44 (lumi) pb and $$\sigma(\mathrm{ p }\mathrm{ p }\to\mathrm{ W }\mathrm{ Z };\ \sqrt{s} = 8\, \mathrm{TeV}) =$$ 24.09 $$\pm$$ 0.87 (stat) $$\pm$$ 1.62 (syst) $$\pm$$ 0.63 (lumi) pb. Differential cross sections with respect to the Z boson p$$_{\mathrm{T}}$$, the leading jet $$p_{\mathrm{T}}$$, and the number of jets are obtained using the $$\sqrt{s} =$$ 8 TeV data. Lastly, the results are consistent with standard model predictions and constraints on anomalous triple gauge couplings are obtained.« less
  • 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 branchingmore » 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.« less