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CMS-TOP-11-020 ; CERN-PH-EP-2013-133
Measurement of the W-boson helicity in top-quark decays from $ \mathrm{ t \bar{t} } $ production in lepton+jets events in pp collisions at $\sqrt{s}$ = 7 TeV
CMS Collaboration
19 August 2013
J. High Energy Phys. 10 (2013) 167
Abstract: The W-boson helicity fractions in top-quark decays are measured with $t\bar{t}$ events in the lepton+jets final state, using proton-proton collisions at a centre-of-mass energy of 7 TeV, collected in 2011 with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 5.0 inverse femtobarns. The measured fractions of longitudinal, left-, and right-handed helicity are $F_0=0.682 \pm 0.030 (stat.) \pm 0.033 (syst.)$, $F_L=0.310 \pm 0.022 (stat.) \pm 0.022 (syst.)$, and $F_R= 0.008 \pm 0.012 (stat.) \pm 0.014 (syst.)$, consistent with the standard model predictions. The measured fractions are used to probe the existence of anomalous Wtb couplings. Exclusion limits on the real components of the anomalous couplings $g_L, g_R$ are also derived.
Links: e-print arXiv:1308.3879 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; Public twiki page ; HepData record ; CADI line (restricted) ;
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Compact Muon Solenoid
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