Experimental evidence for the non-Abelian nature of QCD from a study of multijet events produced in /ital e//sup +/e/sup /minus// annihilation

We present evidence for the non-Abelian nature of QCD from a study ofmultijet events produced in /ital e//sup +/e/sup /minus// annihilations from..sqrt../ital s/ =50 to 57 GeV in the AMY detector at the KEK storage ring TRISTAN. Acomparison of the three-jet event fraction at TRISTAN to the fraction of theDESY storage ring PETRA shows that the QCD coupling strength ..cap alpha../sub /ital s//decreases with increasing /ital Q//sup 2/. In addition, measurements of theangular distributions of four-jet events show evidence for the triple-gluonvertex.