Search for Anomalous Top-Quark Couplings with the D0 Detector

Anomalous $Wtb$ couplings modify the angular correlations of the top-quark decay products and change the single top-quark production cross section. We present limits on anomalous top-quark couplings by combining information from $W$ boson helicity measurements in top-quark decays and anomalous coupling searches in the single top-quark final state. We set limits on right-handed vector couplings as well as left-handed and right-handed tensor couplings based on about $1{\mathrm{fb}}^{-1}$ of data collected by the D0 experiment.

Figure 1

$W$ helicity prior (a), (c), (e) and final posterior density (b), (d), (f) for right- vs left-handed vector coupling (a) and (b), left-handed tensor vs left-handed vector coupling (c) and (d), and right-handed tensor vs left-handed vector coupling (e) and (f). The $W$ helicity prior is normalized to a peak value of one and shown as equally spaced contours between zero and one. The posterior density is shown as contours of equal probability density.