GLUON RADIATION AND ENERGY-LOSSES IN TOP-QUARK PRODUCTION

The emission of energetic gluons in tf production in e(+)e(-) annihila tion can have important experimental consequences, in particular on to p quark mass measurements. We present compact, analytical expressions for the gluon energy distribution and its average value at first order in QCD perturbation theory. Our results are valid for arbitrary masse s, collision energies and production currents. We pay particular atten tion to top quark production near threshold, and show that in certain cases the soft gluon approximation is insufficient to describe the rad iation spectrum.