Top quark as a resonance

Abstract

We suggest the description of the dressed fermion propagator with parity non-conservation in the form with separated positive and negative energy poles. We found general form of the $\gamma$-matrix off-shell projectors and corresponding resonance factors. The parity violation leads to deviation of resonance factors from the naive Breit--Wigner form and to appearance of non-trivial spin corrections. However, for top quark with SM vertex the resonance factor returns to the standard one due to $\Gamma /m\ll 1$.

Comments: 8 pages, revtex4, added one section, typos corrected, sync with journal version