On the top-quark polarization and how to measure it

The top quark is expected to decay as a free particle with definite momentum and polarization. Here we consider the possibilities to obtain information about its polarization through the energy and angular distributions of the b-quarks from the decay of the top-quarks produced in $e^{+}{e}^{-}$ annihilation. Analytic expressions and numerical estimates for different beam polarizations are derived.