Energy flow in interjet radiation

We study the distribution of transverse energy, $Q_{\Omega },$ radiated into an arbitrary interjet angular region $\Omega$ in high-$p_T$ two-jet events. Using an approximation that emphasizes radiation directly from the partons that undergo the hard scattering, we find a distribution that can be extrapolated smoothly to $Q_{\Omega }={\Lambda }_{\mathrm{QCD}},$ where it vanishes. This method, which we apply numerically in a valence quark approximation, provides a class of predictions on transverse energy radiated between jets, as a function of jet energy and rapidity, and of the choice of the region $\Omega$ in which the energy is measured. We discuss the relation of our approximation to the radiation from unobserved partons of intermediate energy, whose importance was identified by Dasgupta and Salam.