New directions for top quark polarization in the t-channel process

We define three orthogonal axes to investigate the top-quark polarization in the t-channel single-top process. We provide expressions for the polarization in these axes in terms of anomalous Wtb couplings. It is found that the polarizations in the two axes orthogonal to the spectator quark axis are very sensitive to an anomalous coupling involving a (b) over bar (L)sigma(mu nu)t(R) dipole term. In particular, an asymmetry based on the polarization normal to the production plane is more sensitive to the imaginary part of this coupling than previously studied observables.