Experimental studies on multijet production in e+e- annihilation at PETRA energies

Jet production of the multihadronic data in the whole PETRA energy range of 14.0 to 46.7 GeV has been studied in terms of a cluster algorithm. The relative cluster multiplicities of the data are presented and compared with model calculations, based on 2nd order QCD perturbation theory as well as on leading log QCD calculations including soft gluon interference. The 2nd order perturbative QCD model produces too few spherical and 4-jet like events at the higher energies. The observed descrepancy in the ratio of 4-jet to 3-jet production cannot be explained in the framework of 2nd order perturbative QCD calculations. This result has also consequences for the value of the strong coupling constant αs determined in previous analyses. The leading log QCD model provides a good description of the yield of spherical, 4-jet like events of the data. The differences between the two types of models are also observed on the level of quarks and gluons, and thus are most likely due to the different QCD calculations. 13 refs