Energy flow in interjet radiation

Abstract

We study the distribution of transverse energy, ${Q}_{\ensuremath{\Omega}},$ radiated into an arbitrary interjet angular region $\ensuremath{\Omega}$ 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 ${Q}_{\ensuremath{\Omega}}={\ensuremath{\Lambda}}_{\mathrm{QCD}},$ 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 $\ensuremath{\Omega}$ 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.