Longitudinal top polarisation measurement and anomalous $Wtb$ coupling

Understand

Kinematical distributions of decay products of the top quark carry information on the polarisation of the top as well as on any possible new physics in the decay of the top quark.

• We construct observables in the form of asymmetries in the kinematical distributions to probe their effects.
• Charged-lepton angular distributions in the decay are insensitive to anomalous couplings to leading order.
• Hence these can be a robust probe of top polarisation.