QED-Induced Rapidity-Gap Events at the Z Peak

Abstract

We study rapidity-gap events in $e^{+}{e}^{-}$ annihilation at the Z boson peak initiated by the emission of a virtual photon. This mechanism is suppressed by the QED coupling constant, but it is enhanced due to a large propagator term from the virtual photon. For typical kinematics, we find a smaller event rate than analogous QCD type gap events. In the small jet-pair invariant mass limit, the QED type events follow a $1+{\cos }^2\theta$ distribution in the jet-pair scattering angle, instead of the ${\sin }^2\theta$ distribution of the QCD case.

Comments: 13 pages, plain TeX (needs the PHYZZX macros), 4 figures in PostScript. SLAC-PUB-6116, DOE/ER/40762-009, U of Md. PP \#93-198