COLOR CORRELATIONS AND MULTIPLICITIES IN TOP EVENTS

In events of the type e+ e- --> ttBAR --> bW+bW-BAR, particle producti on could depend in a non-trivial way on the kinematics of the process. Energetic perturbative gluon radiation can be generated (when kinemat ically allowed) by the original ttBAR system and by the t --> bW+ and tBAR --> bW-BAR decays, with negligible interference between the produ ction and decay stages and between the t and tBAR decays. Soft perturb ative gluon emission and non-perturbative fragmentation does introduce a correlation, however. To illustrate the size of these effects, we s tudy the multiplicity as a function of the angle between the b and bBA R jets, close to the ttBAR threshold. Also potential uncertainties in top mass determinations are briefly addressed.