Measurement of the W boson helicity using \ttbar\ events in the dilepton final state at sqrt(s) = 8 TeV

Collaboration
2015
15 pages
Report number:
  • CMS-PAS-TOP-14-017
Experiments:

Citations per year

201320162019202220241032
Abstract:
A measurement of the W boson helicity fractions in top quark decays is presented. The measurement is performed using a sample of top quark pair events with two opposite-sign leptons (electron or muon) in the final state. The sample was recorded in proton-proton collisions at a center-of-mass energy of 8 TeV, and corresponds to an integrated luminosity of 19.7fb1^{-1}. The longitudinal, left-handed and right-handed helicity fractions are measured to be F0=0.653±0.016(stat)±0.024(syst)F_{\rm 0}=0.653\pm 0.016 (\text{stat}) \pm 0.024 (\text{syst}), FL=0.329±0.009(stat)±0.025(syst)F_{\rm L}=0.329\pm 0.009 (\text{stat}) \pm 0.025 (\text{syst}) and FR=0.018±0.008(stat)±0.026(syst)F_{\rm R}=0.018\pm 0.008 (\text{stat}) \pm 0.026 (\text{syst}), respectively. The results are found to be in agreement with predictions of the standard model.
Note:
  • Preliminary results
  • Data
  • p p: scattering
  • p p: colliding beams
  • top: pair production
  • dilepton: final state
  • top: decay
  • W: helicity
  • W: longitudinal
  • W: right-handed
  • W: left-handed