Study of orientation of three jet events in Z0 hadronic decays using the DELPHI detector

Abstract The study of the orientation of three-jet eventsfrom e + e − → Z 0 → multi- hadronsis presented, in particular the polar angle distributions of the thrustaxis and of the normal to the three-jet plane, and the azimuthal correlations between the hadronplane and the one defined by the beam and thrustaxes. The data are compared with results at lower energy and with QCD predictions. Good agreement with QCD predictions is observed. The scalar gluon theory is excluded by the data.