  In events of the type e+ e- -> t tbar -> b W+ bbar W-, particle production
could depend in a non-trivial way on the kinematics of the process. Energetic
perturbative gluon radiation can be generated (when kinematically allowed) by
the original t tbar system and by the t -> b W+ and tbar -> bbar W- decays,
with negligible interference between the production and decay stages and
between the t and tbar decays. Soft perturbative gluon emission and
non-perturbative fragmentation does introduce a correlation, however. To
illustrate the size of these effects, we study the multiplicity as a function
of the angle between the b and bbar jets, close to the t tbar threshold. Also
potential uncertainties in top mass determinations are briefly addressed.
