Measurement of W gamma and Z gamma production in pp collisions at root s=7 TeV
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Data
2011-07-27
Autores
Chatrchyan, S.
Khachatryan, V.
Sirunyan, A. M.
Tumasyan, A.
Adam, W.
Bergauer, T.
Dragicevic, M.
Eroe, J.
Fabjan, C.
Friedl, M.
Título da Revista
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Título de Volume
Editor
Elsevier B.V.
Resumo
A measurement of W gamma and Z gamma production in proton-proton collisions at root 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 pb(-1). The electron and muon decay channels of the W and Z are used. The total cross sections are measured for photon transverse energy E-T(gamma) > 10 GeV and spatial separation from charged leptons in the plane of pseudorapidity and azimuthal angle Delta R(l.gamma) > 0.7, and with an additional dilepton invariant mass requirement of M-ll > 50 GeV for the Z gamma process. The following cross section times branching fraction values are found: sigma(pp -> W gamma + X) x B(W -> lv) = 56.3 +/- 5.0(stat.) +/- 5.0(syst.) +/- 2.3(lumi.) pb and sigma(pp -> Z gamma + X) x B(Z -> ll) = 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 root s = 7 TeV are set. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.
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Palavras-chave
CMS, Physics, Electroweak
Como citar
Physics Letters B. Amsterdam: Elsevier B.V., v. 701, n. 5, p. 535-555, 2011.