Abstract
We present a measurement of the fractions and of longitudinally polarized and right-handed bosons in top-quark decays using data collected with the CDF II detector. The data set used in the analysis corresponds to an integrated luminosity of approximately . We select candidate events with one lepton, at least four jets, and missing transverse energy. Our helicity measurement uses the decay angle , which is defined as the angle between the momentum of the charged lepton in the boson rest frame and the momentum in the top-quark rest frame. The distribution in the data is determined by full kinematic reconstruction of the candidates. We find and , which is consistent with the standard model prediction. We set an upper limit on the fraction of right-handed bosons of at the 95% confidence level.
- Received 8 December 2006
DOI:https://doi.org/10.1103/PhysRevD.75.052001
©2007 American Physical Society