WandZ0decays into quarks plus a photon or a gluon

We study the decays $W\to q\overline{q}\gamma$, $W\to q\overline{q}g$, $Z^0\to q\overline{q}\gamma$, and $Z^0\to q\overline{q}g$ within a unified approach. Several interesting properties such as asymmetries in the decay spectra, vanishing Dalitz plots, etc., are found in $W\to q\overline{q}\gamma$ and traced to the presence of a $W-\gamma -W$ coupling as given by gauge theories. We derive and compare differential and total decay rates for processes with and without such a triple-boson coupling which in general acts as a suppression factor. Three-jet decays $W\to q\overline{q}g$ and $Z^0\to q\overline{q}g$, not suppressed by such a coupling, have appreciable branching ratios. The possibility of studying more exotic three-jet decays such as $Z^0\to \mathrm{ggg}$ is discussed briefly.