Three-Jet Event Orientation in e+e- Annihilation: New Tests of the Standard Model
arXiv:hep-ph/9701424 · doi:10.1016/S0370-2693(97)00358-4
Abstract
We discuss the orientation of e+e- -> q qbar g events in terms of the polar and azimuthal angles of the event plane w.r.t. the electron beam direction. We define an asymmetry of the azimuthal-angle distribution, which, along with the left-right forward-backward polar-angle asymmetry, is sensitive to parity-violating effects in three-jet events; these have yet to be explored experimentally. We have evaluated these observables at O(alpha_s) in perturbative QCD and present their dependence on longitudinal beam polarisation and c.m. energy. We also define a moments analysis in terms of the orientation angles that allows a new and more detailed test of QCD by isolating the six independent helicity cross-sections.
15 pages, 5 figures in eps format. This version replaces the garbled Figure 2 in the original submission. Submitted to Physics Letters B.